Practical organic chemistry:
Detection of elements (N, S, halogens);
Detection and identification of the following functional groups:
hydroxyl (alcoholic and phenolic),
carbonyl (aldehyde and ketone),
carboxyl, amino and nitro;
Chemical methods of separation of mono-functional organic compounds from binary mixtures.
---------------
The objective is to write 10 points
1.Lassaigne test is used for detecting N,S, halogens.
2.Sodium extract of the given compound is prepared first to do Lassaigne test.
3.Ferrous sulphate is used for nitrogen detection, acetic acid and lead acetate for detecting sulphur and NH4OH is used for detecting halogens.
4. Sodium test is used for detecting OH group
5. Ferric chloride test is used detecting phenolic group.
6. 2,4 dinitrophenylhydrazine test used to find the presence of carbonyl group.
7. Tollens reagent test is used for detecting aldehydic group.
8. If a carbonyl group is present, but aldehydic group is not detected, it means ketonic group is there.
9. Bicarbonate test will indicte carboxylic group -COOH
10. Isocyanide test will indicate presence of amine -NH2 group.
Detailed Review point posts follow this post
Tampilkan postingan dengan label Core-Points. Tampilkan semua postingan
Tampilkan postingan dengan label Core-Points. Tampilkan semua postingan
Selasa, 22 Januari 2008
Minggu, 20 Januari 2008
Core Points for Revision
IIT JEE Chemistry
I just completed posting around 10 points for each chapter. It took me 5 days to do the posting even though most of it was posting from the earlier study guide posts. This posting helped to me to look at all the chapters in a short time and also made me notice the gaps in various chapters in thes study guide. Visitors can take the basic framework and add the points they wish to add to the list.
Now I shall post more detailed points for revision. I plan to collect 100 points for each chapter, built around the core points.
I just completed posting around 10 points for each chapter. It took me 5 days to do the posting even though most of it was posting from the earlier study guide posts. This posting helped to me to look at all the chapters in a short time and also made me notice the gaps in various chapters in thes study guide. Visitors can take the basic framework and add the points they wish to add to the list.
Now I shall post more detailed points for revision. I plan to collect 100 points for each chapter, built around the core points.
Sabtu, 19 Januari 2008
IIT JEE Chemistry Ch 1. THE CONCEPTS - Core Points for Review
JEE Syllabus
General topics:
The concept of atoms and molecules;
Dalton's atomic theory;
Mole concept;
Chemical formulae;
Balanced chemical equations;
Calculations (based on mole concept) involving common oxidation-reduction, neutralisation, and displacement reactions;
Concentration in terms of mole fraction, molarity, molality and normality.
---------
Stochiometric coefficients or numbers: The numbers which appear before the chemical symbols in a chemical equation.
Chemical equation gives information about moles of various reactants and products. Hence molar masses involved in the reaction and molar masses of products.
Mass percentage of substance in a system
Mole fraction of a substance in a system
Molarity = Amount of a substance (in mol)/Volume of solution expressed in dm^3
It is applicable to solutions only.
The unit of molarity is mol dm^-3. It is commonly abbreviated by the symbol M and is spelled as molar.
Molality = Amount of a a substance (in mol)/Mass of solvent expressed in kg
It is also applicable to solutions only
CONCEPT OF EQUIVALENT
__________________________
"One equivalent of a substance in a reaction is defined as the amount of substance which reacts or liberates 1 mol of electrons (or H^+ or OH^- ions).
Some more points to be posted
General topics:
The concept of atoms and molecules;
Dalton's atomic theory;
Mole concept;
Chemical formulae;
Balanced chemical equations;
Calculations (based on mole concept) involving common oxidation-reduction, neutralisation, and displacement reactions;
Concentration in terms of mole fraction, molarity, molality and normality.
---------
Stochiometric coefficients or numbers: The numbers which appear before the chemical symbols in a chemical equation.
Chemical equation gives information about moles of various reactants and products. Hence molar masses involved in the reaction and molar masses of products.
Mass percentage of substance in a system
Mole fraction of a substance in a system
Molarity = Amount of a substance (in mol)/Volume of solution expressed in dm^3
It is applicable to solutions only.
The unit of molarity is mol dm^-3. It is commonly abbreviated by the symbol M and is spelled as molar.
Molality = Amount of a a substance (in mol)/Mass of solvent expressed in kg
It is also applicable to solutions only
CONCEPT OF EQUIVALENT
__________________________
"One equivalent of a substance in a reaction is defined as the amount of substance which reacts or liberates 1 mol of electrons (or H^+ or OH^- ions).
Some more points to be posted
IIT JEE Ch.2. GASEOUS, LIQUID AND SOLID STATES - Core Points for Revision
JEE syllabus
Gaseous and liquid states:
Absolute scale of temperature,
ideal gas equation;
Deviation from ideality,
van der Waals equation;
Kinetic theory of gases, average,
root mean square and most probable velocities and their relation with temperature; Law of partial pressures;
Vapour pressure;
Diffusion of gases.
Solid state:
Classification of solids,
crystalline state,
seven crystal systems (cell parameters a, b, c, alpha, beta, gamma),
close packed structure of solids (cubic), packing in fcc, bcc and hcp lattices; Nearest neighbours,
ionic radii,
simple ionic compounds,
point defects.
----------------------
pV = nRT
Vander Waals correction
[p + n²a/V²] [V-nb] = nRT
Graham's Law of Diffusion: The rate of diffusion of a gas is inversely proportional to the square root of its density or molar mass.
Liquids
Vapour pressure
Teh vapour pressure of a liquid may be defined as the pressure of vapour in equilibrium with the liquid. It increases with increase in temperature.
Solid State
Solids can be broadly classified into two categories: crystalline and amorphous.
Classification crystalline solids based on bond type:
Molecular
ionic
covalent
metallic
a space lattice represents a three dimensional translational repetition of the centres of gravity of the units of pattern in the crystals by means of points. These points are called lattice points.
Unit cell: A unit cell represents a parallelopiped obtained by connecting the lattice point such that each parallelopiped contains a complete unit of pattern of the crystal. By stacking of the parallelopipeds the entire crystal structure can be generated.
Parameters to describe a unit cell: Six parameters are required. These are the three basic vectors along three crystallographic axes(a,b, and c) and three angles between the crystallographic axes(α,β,γ).
Based on the presence of certain rotation axes in the unit cell, crystals can be classifed into seven categories
Triclinic
Monoclinic
Orthoclinic
Trigonal
Tetragonal
Hexagonal
packing of crystals; Body centred cubic(bcc), Hexagonal closed packed 9hcp) and cubical close packed (ccp)
Point defects: Schottsky defects, Frenkel defects
Gaseous and liquid states:
Absolute scale of temperature,
ideal gas equation;
Deviation from ideality,
van der Waals equation;
Kinetic theory of gases, average,
root mean square and most probable velocities and their relation with temperature; Law of partial pressures;
Vapour pressure;
Diffusion of gases.
Solid state:
Classification of solids,
crystalline state,
seven crystal systems (cell parameters a, b, c, alpha, beta, gamma),
close packed structure of solids (cubic), packing in fcc, bcc and hcp lattices; Nearest neighbours,
ionic radii,
simple ionic compounds,
point defects.
----------------------
pV = nRT
Vander Waals correction
[p + n²a/V²] [V-nb] = nRT
Graham's Law of Diffusion: The rate of diffusion of a gas is inversely proportional to the square root of its density or molar mass.
Liquids
Vapour pressure
Teh vapour pressure of a liquid may be defined as the pressure of vapour in equilibrium with the liquid. It increases with increase in temperature.
Solid State
Solids can be broadly classified into two categories: crystalline and amorphous.
Classification crystalline solids based on bond type:
Molecular
ionic
covalent
metallic
a space lattice represents a three dimensional translational repetition of the centres of gravity of the units of pattern in the crystals by means of points. These points are called lattice points.
Unit cell: A unit cell represents a parallelopiped obtained by connecting the lattice point such that each parallelopiped contains a complete unit of pattern of the crystal. By stacking of the parallelopipeds the entire crystal structure can be generated.
Parameters to describe a unit cell: Six parameters are required. These are the three basic vectors along three crystallographic axes(a,b, and c) and three angles between the crystallographic axes(α,β,γ).
Based on the presence of certain rotation axes in the unit cell, crystals can be classifed into seven categories
Triclinic
Monoclinic
Orthoclinic
Trigonal
Tetragonal
Hexagonal
packing of crystals; Body centred cubic(bcc), Hexagonal closed packed 9hcp) and cubical close packed (ccp)
Point defects: Schottsky defects, Frenkel defects
IIT JEE Ch.3. ATOMIC STRUCTURE Core Points for Revision
JEE Syllabus
Atomic structure
Bohr model, spectrum of hydrogen atom, quantum numbers;
Wave-particle duality, de Broglie hypothesis;
Uncertainty principle;
Quantum mechanical picture of hydrogen atom (qualitative treatment), shapes of s, p and d orbitals;
Electronic configurations of elements (up to atomic number 36);
Aufbau principle;
Pauli's exclusion principle and Hund's rule;
----------------
In 1913, Niels Bohr proposed a model of the atom. He proposed that the electrons in an atom could only be in certain orbits, or energy levels, around the nucleus. Refinement of Bohr theory led to the modern theory of atomic structure based on quantum mechanics.
Bohr's model is based on particle theory.
As wave-particle duality which says that all micromatter particle exhibit dualitya new model is proposed.
Debroglie p = h/λ
Uncertainty principle Δp* Δx ≥h/4π
The quantum mechanics model
Principal quantum number-Shell,Azimuthal quantum number-sublevel,Magnetic quantum number-orbital, spin quantum number
The orbits are called as shells. The energy level of orbits or shells increases as they increase in distance from the nucleus of the atom. The orbits or shells are represented by numbers as 1,2,3,4,5,6 or 7. They are represented by letters as K,L,M,N,O,P,Q.
Sublevel of an Orbit
The energy levels, or orbits or shells are further divided into sublevels, or subshells. These subshells are designated by letters: s for the first possible sublevel, p for the second possible sublevel, d for the third, f for the fourth, g for the fifth, and from here on they simply go in alphabets.
The number of sublevels of each energy level is equal to the number of the energy levels. This means energy level 1, the K shell will have only one sub levels – s sublevel. The energy level 2, the L shell will have 2 sub levels – s and p.
Orbitals
Sublevels have further divisions called orbitals. Electrons are found in these orbitals. Each orbital contains two electrons.
“s” sublevel has only one orbital. “p” sublevel has 3 orbitals. “d” sublevel has 5 orbitals. “f” sublevel has 7 orbitals.
The two electons in each orbital spin in different directions.
Shape of Orbitals
1. Spherical shape for s.
2. Dumbbell shape for orbitals of p.
3. Four-lobed shape for orbitals of d.
4. Complex shape for all orbitals of higher sublevels.
Pauli's exclusion principle: No two electrons can have all four same quantum numbers
Electrons occupy the lowest energy sublevels that are available. This is known as ‘aufbau’ order or principles.
Hund’s rule says that, for any set of orbitals of equal energy say p orbitals of orbit 2, there is one electron is each orbital before the second electron enters or occupies an orbital.
The energy level of some sublevels at higher orbits is less than the some sublevels at lower orbitals. This fact is to be kept in mind when electron configuration is determined for any atom. The increasing order of energy levels of sublevels is:
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f*, 5d, 6p, 7s, 5f*, 6d, 7p, 8s
Atomic structure
Bohr model, spectrum of hydrogen atom, quantum numbers;
Wave-particle duality, de Broglie hypothesis;
Uncertainty principle;
Quantum mechanical picture of hydrogen atom (qualitative treatment), shapes of s, p and d orbitals;
Electronic configurations of elements (up to atomic number 36);
Aufbau principle;
Pauli's exclusion principle and Hund's rule;
----------------
In 1913, Niels Bohr proposed a model of the atom. He proposed that the electrons in an atom could only be in certain orbits, or energy levels, around the nucleus. Refinement of Bohr theory led to the modern theory of atomic structure based on quantum mechanics.
Bohr's model is based on particle theory.
As wave-particle duality which says that all micromatter particle exhibit dualitya new model is proposed.
Debroglie p = h/λ
Uncertainty principle Δp* Δx ≥h/4π
The quantum mechanics model
Principal quantum number-Shell,Azimuthal quantum number-sublevel,Magnetic quantum number-orbital, spin quantum number
The orbits are called as shells. The energy level of orbits or shells increases as they increase in distance from the nucleus of the atom. The orbits or shells are represented by numbers as 1,2,3,4,5,6 or 7. They are represented by letters as K,L,M,N,O,P,Q.
Sublevel of an Orbit
The energy levels, or orbits or shells are further divided into sublevels, or subshells. These subshells are designated by letters: s for the first possible sublevel, p for the second possible sublevel, d for the third, f for the fourth, g for the fifth, and from here on they simply go in alphabets.
The number of sublevels of each energy level is equal to the number of the energy levels. This means energy level 1, the K shell will have only one sub levels – s sublevel. The energy level 2, the L shell will have 2 sub levels – s and p.
Orbitals
Sublevels have further divisions called orbitals. Electrons are found in these orbitals. Each orbital contains two electrons.
“s” sublevel has only one orbital. “p” sublevel has 3 orbitals. “d” sublevel has 5 orbitals. “f” sublevel has 7 orbitals.
The two electons in each orbital spin in different directions.
Shape of Orbitals
1. Spherical shape for s.
2. Dumbbell shape for orbitals of p.
3. Four-lobed shape for orbitals of d.
4. Complex shape for all orbitals of higher sublevels.
Pauli's exclusion principle: No two electrons can have all four same quantum numbers
Electrons occupy the lowest energy sublevels that are available. This is known as ‘aufbau’ order or principles.
Hund’s rule says that, for any set of orbitals of equal energy say p orbitals of orbit 2, there is one electron is each orbital before the second electron enters or occupies an orbital.
The energy level of some sublevels at higher orbits is less than the some sublevels at lower orbitals. This fact is to be kept in mind when electron configuration is determined for any atom. The increasing order of energy levels of sublevels is:
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f*, 5d, 6p, 7s, 5f*, 6d, 7p, 8s
IIT JEE Ch. 4. PERIODICITY OF PROPERTIES OF ELEMENTS - Revision Points
JEE Syllabus
No specific syllabus on this topic
------------
I want to paste the periodic table in this post. It is important to know the atomic numbers of many elements as well as the group wise elements and periodwise elements. Many times, the answers to questions can be given if we know to which group the elements in the question belong to by analogy to the behaviour of popular elements like Na, Mg, C,N,O,S, and F.
So periodic table is an essential revision
No specific syllabus on this topic
------------
I want to paste the periodic table in this post. It is important to know the atomic numbers of many elements as well as the group wise elements and periodwise elements. Many times, the answers to questions can be given if we know to which group the elements in the question belong to by analogy to the behaviour of popular elements like Na, Mg, C,N,O,S, and F.
So periodic table is an essential revision
IIT JEE Ch.5. BONDING AND MOLECULAR STRUCTURE -Core Points
JEE Syllabus
Orbital overlap and covalent bond;
Hybridisation involving s, p and d orbitals only;
Orbital energy diagrams for homonuclear diatomic species;
Hydrogen bond;
Polarity in molecules, dipole moment (qualitative aspects only);
VSEPR model and shapes of molecules (linear, angular, triangular, square planar, pyramidal, square pyramidal, trigonal bipyramidal, tetrahedral and octahedral).
-------------------
Exceptions to octet rule
Hydrogen molecule only 2 electrons make it stable.
Incomplete octet of central atom
LiCl
BeH2
BeCl2
BH3
BF3
LiCl 4 electrons around central Li-atom
BeCl2 4 electrons around central Be-atom
BF3 6 electrons around central B-atom
Expanded octet of the central atom
PF5 has ten around P
SF6 hs twelve around S
IF7 has fourteen electrons around I
H2SO4 12 electrons around sulphur atoms
Odd elctron molecules
Nitric oxide, NO
Nitrogen 7 shared electrons
Oxygen 8
Nitrogen dioxide, NO2(there is a coordinate bond)
Nitrogen 7
both oxygens 8
------------------
Exceptions to octet rule
Hydrogen molecule only 2 electrons make it stable.
Incomplete octet of central atom
LiCl
BeH2
BeCl2
BH3
BF3
LiCl 4 electrons around central Li-atom
BeCl2 4 electrons around central Be-atom
BF3 6 electrons around central B-atom
Expanded octet of the central atom
PF5 has ten around P
SF6 hs twelve around S
IF7 has fourteen electrons around I
H2SO4 12 electrons around sulphur atoms
Odd elctron molecules
Nitric oxide, NO
Nitrogen 7 shared electrons
Oxygen 8
Nitrogen dioxide, NO2(there is a coordinate bond)
Nitrogen 7
both oxygens 8
Hydrogen Bonding
The attractive force which binds hydrogen atom of one molecule with electronegative atom (F,O or N) of another molecule is known as hydrogen bond or hydrogen bonding.
VSEPR model and shapes of molecules
linear - 2 electron pairs
angular,
triangular,- 3 electron pairs
square planar,
pyramidal,
square pyramidal,
trigonal bipyramidal,
tetrahedral - 4 electron pairs
octahedral).
The relation between number of electron pairs around the central atom and shape of molecule to be filled
Orbital overlap and covalent bond;
Hybridisation involving s, p and d orbitals only;
Orbital energy diagrams for homonuclear diatomic species;
Hydrogen bond;
Polarity in molecules, dipole moment (qualitative aspects only);
VSEPR model and shapes of molecules (linear, angular, triangular, square planar, pyramidal, square pyramidal, trigonal bipyramidal, tetrahedral and octahedral).
-------------------
Exceptions to octet rule
Hydrogen molecule only 2 electrons make it stable.
Incomplete octet of central atom
LiCl
BeH2
BeCl2
BH3
BF3
LiCl 4 electrons around central Li-atom
BeCl2 4 electrons around central Be-atom
BF3 6 electrons around central B-atom
Expanded octet of the central atom
PF5 has ten around P
SF6 hs twelve around S
IF7 has fourteen electrons around I
H2SO4 12 electrons around sulphur atoms
Odd elctron molecules
Nitric oxide, NO
Nitrogen 7 shared electrons
Oxygen 8
Nitrogen dioxide, NO2(there is a coordinate bond)
Nitrogen 7
both oxygens 8
------------------
Exceptions to octet rule
Hydrogen molecule only 2 electrons make it stable.
Incomplete octet of central atom
LiCl
BeH2
BeCl2
BH3
BF3
LiCl 4 electrons around central Li-atom
BeCl2 4 electrons around central Be-atom
BF3 6 electrons around central B-atom
Expanded octet of the central atom
PF5 has ten around P
SF6 hs twelve around S
IF7 has fourteen electrons around I
H2SO4 12 electrons around sulphur atoms
Odd elctron molecules
Nitric oxide, NO
Nitrogen 7 shared electrons
Oxygen 8
Nitrogen dioxide, NO2(there is a coordinate bond)
Nitrogen 7
both oxygens 8
Hydrogen Bonding
The attractive force which binds hydrogen atom of one molecule with electronegative atom (F,O or N) of another molecule is known as hydrogen bond or hydrogen bonding.
VSEPR model and shapes of molecules
linear - 2 electron pairs
angular,
triangular,- 3 electron pairs
square planar,
pyramidal,
square pyramidal,
trigonal bipyramidal,
tetrahedral - 4 electron pairs
octahedral).
The relation between number of electron pairs around the central atom and shape of molecule to be filled
IIT JEE Ch. 6 ENERGETICS Core Points for Revision
JEE Syllabus
Energetics:
First law of thermodynamics;
Internal energy, work and heat,
pressure-volume work;
Enthalpy,
Hess's law;
Heat of reaction, fusion and vapourization;
Second law of thermodynamics;
Entropy;
Free energy;
Criterion of spontaneity.
------------------
First law of thermodynamics;
Energy cannot be created or destroyed.
U = q + w
Internal energy of matter is equal to kinetic energy and potential energy.
The change in internal energy is equal to heat transferred and work done between the system and the surroundings.
Pressure volume work: If the pressure is constant and the matter expands, the work done is given by p * change in volume. This in termed as pressure volume work.
Enthalpy = U + pv
Hess's Law
Hess's Law states that the enthalpy change for a reaction that occurs in many steps is the same as if it occurred in one step. Another way to put this is if several reactions add up to some total reaction, then their enthalpy changes will add up to the enthalpy change for the total reaction.
Second law of thermodynamics
In general it is impossible to perform a transformation whose only final result is to convert into useful work heat extracted from a source that is at the same temperature throughout. This statement is Lord Kelvin's version of the second law of thermodynamics. Another version of this law, formulated by R. J. E. Clausius, states that a transformation is impossible whose only final result is to transfer heat from a body at a given temperature to a body at higher temperature; in other words, the spontaneous flow of heat from hot to cold bodies is reversible only with the expenditure of mechanical or other nonthermal energy.
The Second law of Thermodynamics states that every spontaneous change is accompanied by an increase in entropy which is a measure of the randomness or disorder of a system.
Energetics:
First law of thermodynamics;
Internal energy, work and heat,
pressure-volume work;
Enthalpy,
Hess's law;
Heat of reaction, fusion and vapourization;
Second law of thermodynamics;
Entropy;
Free energy;
Criterion of spontaneity.
------------------
First law of thermodynamics;
Energy cannot be created or destroyed.
U = q + w
Internal energy of matter is equal to kinetic energy and potential energy.
The change in internal energy is equal to heat transferred and work done between the system and the surroundings.
Pressure volume work: If the pressure is constant and the matter expands, the work done is given by p * change in volume. This in termed as pressure volume work.
Enthalpy = U + pv
Hess's Law
Hess's Law states that the enthalpy change for a reaction that occurs in many steps is the same as if it occurred in one step. Another way to put this is if several reactions add up to some total reaction, then their enthalpy changes will add up to the enthalpy change for the total reaction.
Second law of thermodynamics
In general it is impossible to perform a transformation whose only final result is to convert into useful work heat extracted from a source that is at the same temperature throughout. This statement is Lord Kelvin's version of the second law of thermodynamics. Another version of this law, formulated by R. J. E. Clausius, states that a transformation is impossible whose only final result is to transfer heat from a body at a given temperature to a body at higher temperature; in other words, the spontaneous flow of heat from hot to cold bodies is reversible only with the expenditure of mechanical or other nonthermal energy.
The Second law of Thermodynamics states that every spontaneous change is accompanied by an increase in entropy which is a measure of the randomness or disorder of a system.
IIt JEE Ch. 7. CHEMICAL EQUILIBRIA - Core Points for Revision
JEE Syllabus
Chemical equilibrium:
Law of mass action;
Equilibrium constant,
Le Chatelier's principle (effect of concentration, temperature and pressure); Significance of ΔG and ΔGo in chemical equilibrium;
Solubility product, common ion effect,
pH and buffer solutions;
Acids and bases (Bronsted and Lewis concepts);
Hydrolysis of salts.
The syllabus has two main components: Equilibrium among ions and equilibrium among compounds
---------
There are reactions where one can see the reverse action also to be active and see the equilibrium point. In this case
A + B → C + D and
C+D → A+B both reactions keep taking place.
At the point of equilibrium the rate of both reactions is same. Formation of A+B is equal to consumption of A+B.
Rate of forward reaction = k-f[A][B]
Rate of reverse reaction or backward reaction = k-r[C][D]
Therefore k-f[A][B] = k-r[C]{D]
This gives k-f/k-r = [C]{D]/[A][B]
The equilibrium constant is always written as products by reactants.
For the a general reaction
aA + bB ↔ cC+dD (Normal two arrows are used for reversible reaction. Only one arrow with heads on both sides is used here to tide over the inability to show two arrows.)
k-eq = [C]^c[D]^d/[A]^a[B]^b
The equilibrium constant may or may not have units.
In the case of 2A ↔ 2B +C
The units of equilibrium constant are going to be: (mol/l)^2(mol/l)/(mol/l)^2
= mol/l
Ionic Equilibrium – Introduction
Acids, basess and salts when dissolved n water dissociate to some extent and form ions. In the ion formation, an equilibrium is established between ionized and unionized (whole) molecules as this ionization is a reversible reaction. Such an equilibrium that involves ions is called ionic equilibrium.
Acids and bases definitions (Arrhenius, Bronsted and Lewis)
Arrhenius defined acid as a hydrogen compound which in water solution give hydrogen ions.
He defined base as a hydroxide compound which in water solution gives hydroxide ions.
Lowry and Bronsted
An acid is defined as a substance having a tendency of lose or to donate one or more protons.
A base is defined as a substance having a tendency to accept or add a proton
Lewis Theory of Acids and Bases
Acid: An acid is any substance (molecule, ion or atom) that can accept a lone pair of electrons to form a coordinate bond (*Remember coordinate bond and lone pair topics in chapter on Bonding)
Base: Base is any species (molecule, ion or atom) that can donate a lone pair of electrons to form a co-ordinate bond.
Ostwald’s Dilution law
α = SQRT(K/C)
α = Total mole of acid or base dissociated/Total mole of acid or base present in the solution
Chemical equilibrium:
Law of mass action;
Equilibrium constant,
Le Chatelier's principle (effect of concentration, temperature and pressure); Significance of ΔG and ΔGo in chemical equilibrium;
Solubility product, common ion effect,
pH and buffer solutions;
Acids and bases (Bronsted and Lewis concepts);
Hydrolysis of salts.
The syllabus has two main components: Equilibrium among ions and equilibrium among compounds
---------
There are reactions where one can see the reverse action also to be active and see the equilibrium point. In this case
A + B → C + D and
C+D → A+B both reactions keep taking place.
At the point of equilibrium the rate of both reactions is same. Formation of A+B is equal to consumption of A+B.
Rate of forward reaction = k-f[A][B]
Rate of reverse reaction or backward reaction = k-r[C][D]
Therefore k-f[A][B] = k-r[C]{D]
This gives k-f/k-r = [C]{D]/[A][B]
The equilibrium constant is always written as products by reactants.
For the a general reaction
aA + bB ↔ cC+dD (Normal two arrows are used for reversible reaction. Only one arrow with heads on both sides is used here to tide over the inability to show two arrows.)
k-eq = [C]^c[D]^d/[A]^a[B]^b
The equilibrium constant may or may not have units.
In the case of 2A ↔ 2B +C
The units of equilibrium constant are going to be: (mol/l)^2(mol/l)/(mol/l)^2
= mol/l
Ionic Equilibrium – Introduction
Acids, basess and salts when dissolved n water dissociate to some extent and form ions. In the ion formation, an equilibrium is established between ionized and unionized (whole) molecules as this ionization is a reversible reaction. Such an equilibrium that involves ions is called ionic equilibrium.
Acids and bases definitions (Arrhenius, Bronsted and Lewis)
Arrhenius defined acid as a hydrogen compound which in water solution give hydrogen ions.
He defined base as a hydroxide compound which in water solution gives hydroxide ions.
Lowry and Bronsted
An acid is defined as a substance having a tendency of lose or to donate one or more protons.
A base is defined as a substance having a tendency to accept or add a proton
Lewis Theory of Acids and Bases
Acid: An acid is any substance (molecule, ion or atom) that can accept a lone pair of electrons to form a coordinate bond (*Remember coordinate bond and lone pair topics in chapter on Bonding)
Base: Base is any species (molecule, ion or atom) that can donate a lone pair of electrons to form a co-ordinate bond.
Ostwald’s Dilution law
α = SQRT(K/C)
α = Total mole of acid or base dissociated/Total mole of acid or base present in the solution
IIT JEE Ch.8 ELECTROCHEMISTRY - Core Point for Revision
JEE Syllabus
Electrochemistry:
Electrochemical cells and cell reactions;
Electrode potentials;
Nernst equation and its relation to ΔG;
Electrochemical series,
emf of galvanic cells;
Electrolysis
Faraday's laws of electrolysis;
Electrolytic conductance, specific, equivalent and molar conductance,
Kohlrausch's law;
Concentration cells.
---------------
electrochemical cell
or Voltaic or Galvanic Cells
In this cell, a chemical reaction produces electrical energy.
In this cell, the electrons being transferred from the reducing agent to the oxidizing agent travel through a wire and thus provide an elctric current.
a electrochemical cell is represented as
Ө Zn|ZnSO-4║CuSO-4|Cu In this symbol additionally On zinc side as it is a cathode a - sign is placed in O (as shown) and on Cu side as it is anode a + sign is placed in O.
cell reactions;
Reaction at the electrodes are called half cell reactions as both the elctrodes are kept seperate from physical contact and ion movement only is permitted through salt bridge.
At zinc electrode Zn → Zn^2+ +2e¯ (oxidation)
At Cu electrode: Cu^2+ +2e¯ → Cu (reduction)
Electrode potentials
When an electrode in put in solution of ions, a charge is developed between the solution and the electrode. This charge is termed a electrode potential. The electrode potential cannot be measured individually and it is measured in reference to a standard hydrogen electrode.
Standard Hydrogen Electrode
An electrode in which pure dry hydrogen gas is bubbled at 1 atm and 298K about a platinized platinum plate through a solution containing H^+ ions ( for example - HCl solution)
The emf produced is taken as zero volts. All other potential are expressed with SHE potential as zero.
Nernst Equation: The cell potential of a half cell (as well as that of a complete cell) depends upon the concentrations of involved ions, pressure of the gaseous species (if involved) and the temperature. The relation connecting them is given by the Nernst equation.
It is expressed as
E = E° - (RT/nF)ln Q°
Q° = Product of concentration (or pressure) of products each raised to the corresponding stochiometric number/Product of concentration (or pressure) of reactants each raised to the corresponding stochiometric number
n = number of electrons involved in the hall cell reaction
Electrochemical series is the series in which various elements are arranged in the order of their reduction or oxidation potentials.
Emf of galvanic cells
E(Cell) = E(R) - E(L)
Electrolysis
In electrolytic cell, electric energy is used to cause a chemical reaction to take place.
Faraday's laws of electrolysis:
---------------------------------------
Quantitative Relationships in Electrolytic Cells
Determining the amount of electrical energy necessary for accumulating a given amount material from the electrolytic cell.
First law: It states that the amount of any substance that is liberated at an electrode during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte.
W α Q (w = weight of substance deposited and Q is charge = ampere * time)
Second law: It states tht when the same quantity of electricity is passed through different electrolytes amount of different substances liberated or deposited at the different electrodes are directly proportional to the chemical equivalents9i.e., equivalent weight) of substances.
One faraday (F) is the amount of electrical energy required for flow of 1 mole of electrons.
To three significant digits, 1 faraday equals 96,500 coulombs(coul).
Current flow is measured in amperes (A)which is coulombs/seconds or coul/s,
Electrolytic conductance
The flow of electric current through an electrolytic solution is known as electrolytic conduction.
Electrolytic conduction also follows Ohm's law.
The equivalent conductivity of an electrolyte may be defined as the conductance of a volume of solution containing one equivalent mass of a dissolved substance when placed between two parallel electrodes which are at a unit distance apart, and large enough to contain between them the whole solution.
The molar conductivity of a solution gives the conducting power of ions produced by one molar mass of an electrolyte at any particular concentration.
Kohlrausch's Law on the independence of migrating ions: The molar conductivity of an electrolyte equals the sum of the molar conductivities of the cations and the anions; n = number of anions or cations.
Λ = v+Λ+ + vˉΛˉ
Concentration cells.
Concentration Cells are electrochemical cells that have two equivalent half-cells of the same material differing only in concentrations. One can calculate the potential developed by such cells using the Nernst Equation. A concentration cell produces a voltage in the process of reaching equilibrium, which will occur when the concentration in both cells are equal.
Concentration cell methods of chemical analysis compare a solution of known concentration with an unknown, determining the concentration of the unknown via the Nernst Equation.
Electrochemistry:
Electrochemical cells and cell reactions;
Electrode potentials;
Nernst equation and its relation to ΔG;
Electrochemical series,
emf of galvanic cells;
Electrolysis
Faraday's laws of electrolysis;
Electrolytic conductance, specific, equivalent and molar conductance,
Kohlrausch's law;
Concentration cells.
---------------
electrochemical cell
or Voltaic or Galvanic Cells
In this cell, a chemical reaction produces electrical energy.
In this cell, the electrons being transferred from the reducing agent to the oxidizing agent travel through a wire and thus provide an elctric current.
a electrochemical cell is represented as
Ө Zn|ZnSO-4║CuSO-4|Cu In this symbol additionally On zinc side as it is a cathode a - sign is placed in O (as shown) and on Cu side as it is anode a + sign is placed in O.
cell reactions;
Reaction at the electrodes are called half cell reactions as both the elctrodes are kept seperate from physical contact and ion movement only is permitted through salt bridge.
At zinc electrode Zn → Zn^2+ +2e¯ (oxidation)
At Cu electrode: Cu^2+ +2e¯ → Cu (reduction)
Electrode potentials
When an electrode in put in solution of ions, a charge is developed between the solution and the electrode. This charge is termed a electrode potential. The electrode potential cannot be measured individually and it is measured in reference to a standard hydrogen electrode.
Standard Hydrogen Electrode
An electrode in which pure dry hydrogen gas is bubbled at 1 atm and 298K about a platinized platinum plate through a solution containing H^+ ions ( for example - HCl solution)
The emf produced is taken as zero volts. All other potential are expressed with SHE potential as zero.
Nernst Equation: The cell potential of a half cell (as well as that of a complete cell) depends upon the concentrations of involved ions, pressure of the gaseous species (if involved) and the temperature. The relation connecting them is given by the Nernst equation.
It is expressed as
E = E° - (RT/nF)ln Q°
Q° = Product of concentration (or pressure) of products each raised to the corresponding stochiometric number/Product of concentration (or pressure) of reactants each raised to the corresponding stochiometric number
n = number of electrons involved in the hall cell reaction
Electrochemical series is the series in which various elements are arranged in the order of their reduction or oxidation potentials.
Emf of galvanic cells
E(Cell) = E(R) - E(L)
Electrolysis
In electrolytic cell, electric energy is used to cause a chemical reaction to take place.
Faraday's laws of electrolysis:
---------------------------------------
Quantitative Relationships in Electrolytic Cells
Determining the amount of electrical energy necessary for accumulating a given amount material from the electrolytic cell.
First law: It states that the amount of any substance that is liberated at an electrode during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte.
W α Q (w = weight of substance deposited and Q is charge = ampere * time)
Second law: It states tht when the same quantity of electricity is passed through different electrolytes amount of different substances liberated or deposited at the different electrodes are directly proportional to the chemical equivalents9i.e., equivalent weight) of substances.
One faraday (F) is the amount of electrical energy required for flow of 1 mole of electrons.
To three significant digits, 1 faraday equals 96,500 coulombs(coul).
Current flow is measured in amperes (A)which is coulombs/seconds or coul/s,
Electrolytic conductance
The flow of electric current through an electrolytic solution is known as electrolytic conduction.
Electrolytic conduction also follows Ohm's law.
The equivalent conductivity of an electrolyte may be defined as the conductance of a volume of solution containing one equivalent mass of a dissolved substance when placed between two parallel electrodes which are at a unit distance apart, and large enough to contain between them the whole solution.
The molar conductivity of a solution gives the conducting power of ions produced by one molar mass of an electrolyte at any particular concentration.
Kohlrausch's Law on the independence of migrating ions: The molar conductivity of an electrolyte equals the sum of the molar conductivities of the cations and the anions; n = number of anions or cations.
Λ = v+Λ+ + vˉΛˉ
Concentration cells.
Concentration Cells are electrochemical cells that have two equivalent half-cells of the same material differing only in concentrations. One can calculate the potential developed by such cells using the Nernst Equation. A concentration cell produces a voltage in the process of reaching equilibrium, which will occur when the concentration in both cells are equal.
Concentration cell methods of chemical analysis compare a solution of known concentration with an unknown, determining the concentration of the unknown via the Nernst Equation.
Jumat, 18 Januari 2008
IIT JEE Ch 9. SOLUTIONS - Core Points for Revision
Jee Syllabus
Solutions:
Raoult's law;
Molecular weight determination from lowering of vapor pressure,
Molecular weight determination from elevation of boiling point
Molecular weight determination from depression of freezing point.
-----------------
Raolt's Law
In the case of a solution of two liquids, A and B, the total vapor pressure Ptot(P total) above the solution is equal to the sum of the vapor pressures of the two components, PA and PB and
PA = PA° * Am
PB = PB° * Bm
Where
PA° = vapour pressure created by 1 mol of liquid A
Am = mole fraction of liquid A in the solution
PB° = vapour pressure created by 1 mol of liquid A
Bm = mole fraction of liquid A in the solution
The pressure exerted by the vapours above the liquid surface in equilibrium with the liquid at a given temperature is called vapour pressure.
If a small amount of non-volatile solute is added to the the solvent, the vapour pressure of the solution becomes less than that of the pure solvent.
Some properties of the solution depend only on the number of solute particles but on the nature of the solute. These are called colligative properties or democratic properties.
The four important ones are:
i) Relative lowering in vapour pressure
ii) elevation in boiling point
iii) depression in freezing point
iv) osmotic pressure
Molecular weight determination from lowering of vapor pressure
Molar mass of a solute can be found from the property of lowering of vapor pressure of a solution.
Mb = (Wb*Ma)/[Wa*(Pa°-Pa)/Pa°]
Wb = weight of solute particles, Wa= weight of solvent
(Pa°-Pa)/Pa° = decrease in vapour pressure of solution
Ma = Molar mass of solvent
Molecular weight determination from elevation of boiling point
Mb = [Kb*Wb*1000]/[ΔTb*Wa]
ΔTb = increase in boiling point of the solution after adding the solute
Kb = molal elevation constant or ebulloscopic constant
= the elevation in boiling point for 1 molal solution, i.e., a solution containing 1 gram mole of solute dissolved in 1000 g of the solvent.
Molecular weight determination from depression of freezing point.
when a non-volatile solute is added to a solvent, the freezing point of the solution is always lower than that of the pure solvent.
The depression in freezing temperature is proportional to the molal concentration of the solution.
ΔTf α m Or ΔTf = Kf*m
Kf is the molal depression constant. also called molal cryoscopic constant. It is defined as the depression in freezing point for 1 molal solution i.e., a solution containing 1 gram mole of solute dissolved in 1000 g of solvent.
Mb = [Kf*Wb*1000]/[ΔTf * Wa]
--------------
For more detailed study guide on the topic
http://iit-jee-chemistry.blogspot.com/2007/10/study-guide-ch-9-solutions.html
Solutions:
Raoult's law;
Molecular weight determination from lowering of vapor pressure,
Molecular weight determination from elevation of boiling point
Molecular weight determination from depression of freezing point.
-----------------
Raolt's Law
In the case of a solution of two liquids, A and B, the total vapor pressure Ptot(P total) above the solution is equal to the sum of the vapor pressures of the two components, PA and PB and
PA = PA° * Am
PB = PB° * Bm
Where
PA° = vapour pressure created by 1 mol of liquid A
Am = mole fraction of liquid A in the solution
PB° = vapour pressure created by 1 mol of liquid A
Bm = mole fraction of liquid A in the solution
The pressure exerted by the vapours above the liquid surface in equilibrium with the liquid at a given temperature is called vapour pressure.
If a small amount of non-volatile solute is added to the the solvent, the vapour pressure of the solution becomes less than that of the pure solvent.
Some properties of the solution depend only on the number of solute particles but on the nature of the solute. These are called colligative properties or democratic properties.
The four important ones are:
i) Relative lowering in vapour pressure
ii) elevation in boiling point
iii) depression in freezing point
iv) osmotic pressure
Molecular weight determination from lowering of vapor pressure
Molar mass of a solute can be found from the property of lowering of vapor pressure of a solution.
Mb = (Wb*Ma)/[Wa*(Pa°-Pa)/Pa°]
Wb = weight of solute particles, Wa= weight of solvent
(Pa°-Pa)/Pa° = decrease in vapour pressure of solution
Ma = Molar mass of solvent
Molecular weight determination from elevation of boiling point
Mb = [Kb*Wb*1000]/[ΔTb*Wa]
ΔTb = increase in boiling point of the solution after adding the solute
Kb = molal elevation constant or ebulloscopic constant
= the elevation in boiling point for 1 molal solution, i.e., a solution containing 1 gram mole of solute dissolved in 1000 g of the solvent.
Molecular weight determination from depression of freezing point.
when a non-volatile solute is added to a solvent, the freezing point of the solution is always lower than that of the pure solvent.
The depression in freezing temperature is proportional to the molal concentration of the solution.
ΔTf α m Or ΔTf = Kf*m
Kf is the molal depression constant. also called molal cryoscopic constant. It is defined as the depression in freezing point for 1 molal solution i.e., a solution containing 1 gram mole of solute dissolved in 1000 g of solvent.
Mb = [Kf*Wb*1000]/[ΔTf * Wa]
--------------
For more detailed study guide on the topic
http://iit-jee-chemistry.blogspot.com/2007/10/study-guide-ch-9-solutions.html
IIT JEE Ch.10. CHEMICAL KINETICS Core Points for Revision
Jee Syllabus
Chemical kinetics:
Rates of chemical reactions;
Order of reactions;
Rate constant;
First order reactions;
Temperature dependence of rate constant (Arrhenius equation).
--------------------------
The topic "Chemical kinetics" consists of reaction rate and reaction mechanism.
Reaction rate is the speed with which a reaction takes place. This shows the rate or speed at which the reactants are consumed and products are formed.
Reaction mechanism is the path by which a reaction takes place.
Rate of reaction
The rate of reaction is a quantity that tells how the concentration of reactants or product changes with time.
So this can be expressed as Δ concentration/Δ time. That is change in concenation divided by time taken for the change.
Molar concentration i.e., moles per liter (M), is used in these equations.
The brackets, [ ] are always used to to indicate molar concentrations.
Rate law
The rate for a reaction is a mathematical expression that relates the rate of reaction to the concentrations of the reactants.
For the reaction aA + bB → products
The rate law is expressed as, rate of reaction is proportional to [A]^x[B]^y.
x and y are determined experimentally. These values can be whole or fractional numbers or zero.
Law of Mass Action
In 1867, Cato Guldberg, and Peter Waage, proposed this law. According to this law, for the rate determining step in a reaction, the rate of reaction is proportional to the product of the concentrations of the reactants, each raised to the power of its coefficient in the balanced equation.
For the reaction aA + bB → cC (when it is a rate determining step)
Rate of reaction is proportional to [A]^a[B]^b
The above proportionality can be written as an equation, by putting in a proportionality constant k.
Rate = k *[A]^a[B]^b
K is called the specific rate constant
Order of Reaction
From the rate law for a reaction order of reaction can be determined.
For a particular species or reactant, the order is equal to the exponent for that species in the rate law.
For example for Rate = k *[A][B]^2
for B the order of reaction is 2. For A it is 1.
The overall order of reaction is equal to the sum of all the individual orders of reactants.
Temperature
As temperature increases, the average kinetic energy increases. So there are more molecules with activation energy and hence reaction rate increases.
As a general approximation, the rate roughly doubles for each 10°C rise in temperature.
Chemical kinetics:
Rates of chemical reactions;
Order of reactions;
Rate constant;
First order reactions;
Temperature dependence of rate constant (Arrhenius equation).
--------------------------
The topic "Chemical kinetics" consists of reaction rate and reaction mechanism.
Reaction rate is the speed with which a reaction takes place. This shows the rate or speed at which the reactants are consumed and products are formed.
Reaction mechanism is the path by which a reaction takes place.
Rate of reaction
The rate of reaction is a quantity that tells how the concentration of reactants or product changes with time.
So this can be expressed as Δ concentration/Δ time. That is change in concenation divided by time taken for the change.
Molar concentration i.e., moles per liter (M), is used in these equations.
The brackets, [ ] are always used to to indicate molar concentrations.
Rate law
The rate for a reaction is a mathematical expression that relates the rate of reaction to the concentrations of the reactants.
For the reaction aA + bB → products
The rate law is expressed as, rate of reaction is proportional to [A]^x[B]^y.
x and y are determined experimentally. These values can be whole or fractional numbers or zero.
Law of Mass Action
In 1867, Cato Guldberg, and Peter Waage, proposed this law. According to this law, for the rate determining step in a reaction, the rate of reaction is proportional to the product of the concentrations of the reactants, each raised to the power of its coefficient in the balanced equation.
For the reaction aA + bB → cC (when it is a rate determining step)
Rate of reaction is proportional to [A]^a[B]^b
The above proportionality can be written as an equation, by putting in a proportionality constant k.
Rate = k *[A]^a[B]^b
K is called the specific rate constant
Order of Reaction
From the rate law for a reaction order of reaction can be determined.
For a particular species or reactant, the order is equal to the exponent for that species in the rate law.
For example for Rate = k *[A][B]^2
for B the order of reaction is 2. For A it is 1.
The overall order of reaction is equal to the sum of all the individual orders of reactants.
Temperature
As temperature increases, the average kinetic energy increases. So there are more molecules with activation energy and hence reaction rate increases.
As a general approximation, the rate roughly doubles for each 10°C rise in temperature.
IIT JEE Ch. 11. SURFACE CHEMISTRY Core Revision Points
JEE syllabus
Surface chemistry:
Elementary concepts of adsorption (excluding adsorption isotherms);
Colloids: types, methods of preparation and general properties;
Elementary ideas of emulsions, surfactants and micelles (only definitions and examples).
--------------
The term adsorption implies the presence of excess concentration of any particular component in one of the three phases of matter (known as adsorbate) at the surface of liquid or solid phase (known as adsorbent) as compared to that present in the bulk of the material.
On the basis of the forces of attraction between adsorbent and adsorbate, two types of adsorption, namely, physisorption (i.e. physical adsorption) and chemisorption, may be identified.
Colloids or sols are the substances whose sizes lie in between the solutes present in a true solution (e.g., salt, sugar) and the solutes present in suspension (e.g., sand).
The diameters of colloidal particles may range from 1 to 100 nm. The particles in colloidal state do not settle down on standing, are not visible and they can pass through a filter paper. However, they do not pass through a perchment paper or animal membrane.
Emulsion is a liquid dispersed in a liquid.
Any substance which can decrease the surface tension of water to a large extent is known as surfactant. Examples of soap and detergents. Such substances have larger concentrations at the surface of water as compared to the bulk of the solution.
Surfactants in solution are often association colloids, that is, they tend to form aggregates of colloidal dimensions, which exist in equilibrium with the molecules or ions from which they are formed. Such aggregates are termed micelles.
Surface chemistry:
Elementary concepts of adsorption (excluding adsorption isotherms);
Colloids: types, methods of preparation and general properties;
Elementary ideas of emulsions, surfactants and micelles (only definitions and examples).
--------------
The term adsorption implies the presence of excess concentration of any particular component in one of the three phases of matter (known as adsorbate) at the surface of liquid or solid phase (known as adsorbent) as compared to that present in the bulk of the material.
On the basis of the forces of attraction between adsorbent and adsorbate, two types of adsorption, namely, physisorption (i.e. physical adsorption) and chemisorption, may be identified.
Colloids or sols are the substances whose sizes lie in between the solutes present in a true solution (e.g., salt, sugar) and the solutes present in suspension (e.g., sand).
The diameters of colloidal particles may range from 1 to 100 nm. The particles in colloidal state do not settle down on standing, are not visible and they can pass through a filter paper. However, they do not pass through a perchment paper or animal membrane.
Emulsion is a liquid dispersed in a liquid.
Any substance which can decrease the surface tension of water to a large extent is known as surfactant. Examples of soap and detergents. Such substances have larger concentrations at the surface of water as compared to the bulk of the solution.
Surfactants in solution are often association colloids, that is, they tend to form aggregates of colloidal dimensions, which exist in equilibrium with the molecules or ions from which they are formed. Such aggregates are termed micelles.
IIt JEE Ch.12. NUCLEAR CHEMISTRY - Core Points for Revision
JEE Syllabus
Nuclear chemistry:
Radioactivity:
isotopes and isobars;
Properties of a, b and g rays;
Kinetics of radioactive decay (decay series excluded),
carbon dating;
Stability of nuclei with respect to proton-neutron ratio;
Brief discussion on fission and fusion reactions.
--------------
The phenomenon of spontaneous emission ofactive radiations from certain substances is called radioactivity and the substances which emit such radiations are called radioactive substances.
Isotopes and Isobars
Atoms of the same element having same atomic number but different mass numbers are called isotopes.
Ex:(235, 92)U (238, 92)U
The atoms of different elements having different atomic numbers but same mass numbers are called isobars.
Ex (40,18)Ar ,(40,19)K , (40,20)Ca
An α particle contains two protons and two neutrons (and is similar to a He nucleus: ).
Beta Radiation (β) is the transmutation of a neutron into a proton and a electron (followed by the emission of the electron from the atom's nucleus:).
Gamma Radiation (γ) involves the emission of electromagnetic energy (similar to light energy) from an atom's nucleus.
Neutron-proton ratio
In the stability zone, for nuclei having atomic number up to 20, the neutron-proton ratio (n/p ratio) is close to unity.
for nuclei having atomic number more than 20, the n/p ratio for stability exceeds unity and goes up to 1.5 for heavier nuclei.
Radioactive decay proceeds according to a principal called the half-life. The half-life (T½) is the amount of time necessary for one-half of the radioactive material to decay.
During the fission of U235, three neutrons are released in addition to the two daughter atoms. If these released neutrons collide with nearby U235 nuclei, they can stimulate the fission of these atoms and start a self-sustaining nuclear chain reaction.As uranium atoms continue to split, a significant amount of energy is released from the reaction. The heat released during this reaction is harvested and used to generate electrical energy.
Nuclear fusion: reactions in which two or more elements "fuse" together to form one larger element, releasing energy in the process. A good example is the fusion of two "heavy" isotopes of hydrogen (deuterium: H2 and tritium: H3) into the element helium.
Carbon dating: The technique is based on the fact that all living matters contain a definite amount of radioactive isotope carbon 14 and after death decay of carbon 14 takes place. The amount of Carbon 14 remaining in the dead matter is determined from this the age of the body is calculated.
Nuclear chemistry:
Radioactivity:
isotopes and isobars;
Properties of a, b and g rays;
Kinetics of radioactive decay (decay series excluded),
carbon dating;
Stability of nuclei with respect to proton-neutron ratio;
Brief discussion on fission and fusion reactions.
--------------
The phenomenon of spontaneous emission ofactive radiations from certain substances is called radioactivity and the substances which emit such radiations are called radioactive substances.
Isotopes and Isobars
Atoms of the same element having same atomic number but different mass numbers are called isotopes.
Ex:(235, 92)U (238, 92)U
The atoms of different elements having different atomic numbers but same mass numbers are called isobars.
Ex (40,18)Ar ,(40,19)K , (40,20)Ca
An α particle contains two protons and two neutrons (and is similar to a He nucleus: ).
Beta Radiation (β) is the transmutation of a neutron into a proton and a electron (followed by the emission of the electron from the atom's nucleus:).
Gamma Radiation (γ) involves the emission of electromagnetic energy (similar to light energy) from an atom's nucleus.
Neutron-proton ratio
In the stability zone, for nuclei having atomic number up to 20, the neutron-proton ratio (n/p ratio) is close to unity.
for nuclei having atomic number more than 20, the n/p ratio for stability exceeds unity and goes up to 1.5 for heavier nuclei.
Radioactive decay proceeds according to a principal called the half-life. The half-life (T½) is the amount of time necessary for one-half of the radioactive material to decay.
During the fission of U235, three neutrons are released in addition to the two daughter atoms. If these released neutrons collide with nearby U235 nuclei, they can stimulate the fission of these atoms and start a self-sustaining nuclear chain reaction.As uranium atoms continue to split, a significant amount of energy is released from the reaction. The heat released during this reaction is harvested and used to generate electrical energy.
Nuclear fusion: reactions in which two or more elements "fuse" together to form one larger element, releasing energy in the process. A good example is the fusion of two "heavy" isotopes of hydrogen (deuterium: H2 and tritium: H3) into the element helium.
Carbon dating: The technique is based on the fact that all living matters contain a definite amount of radioactive isotope carbon 14 and after death decay of carbon 14 takes place. The amount of Carbon 14 remaining in the dead matter is determined from this the age of the body is calculated.
Kamis, 17 Januari 2008
IIT JEE Inorganic Chemistry Ch.13. NON-METALS Core Points for Revision
The Inorganic Chemistry of IIT JEE syllabus is covered in six chapters the first one being nonmetals. The rest of the chapters are compounds of metals, compounds of nonmetals, transient elements, ores/minerals and extractive metallury and qualitative analysis.
Seperate posts are there for each chapter.
---------------------------------
IIT JEE Syllabus NON-METALS
Isolation/preparation and properties of the following non-metals:
Boron,
silicon,
nitrogen,
phosphorus,
oxygen,
sulphur and
halogens;
Properties of allotropes of
carbon (only diamond and graphite),
phosphorus and
sulphur.
Boron (B)
Z = 5, 1s²2s²2px¹
Boron belongs to 13th group.
Method of obtaining Boron
By the reduction of boric oxide by an electropositive metal like magnesium.
silicon (Si) -
Atomic Number is 14. 1s²2s²2p^63s²3p²
Method of obtaining Silicon: Heating finely divided silica with magnesium powder.
Sulphur (S)
Partial combustion of Hydrogen sulphide produce sulphur.
Halogens
Flourine (F), Chlorine (Cl), Bromine (Br), Iodine (I).
Chlorine is yellow green gas
Bromine is reddish brown liquid
Iodine is steel grey solid
Allotrope
• Allotropes are elements that can exist in two or more different physical forms
• Diamond, graphite and buckminster fullerine are allotropes of carbon.
• The allotropes of carbon are all the element carbon. The type of carbon is determined from the bonding that occurs.
The carbon atoms in graphite are arranged in flat sheets that slide easily over each other, while the atoms in diamond are bonded in a complex, honeycombed structure that makes the solid much harder.
Atmospheric oxygen (O2) and ozone (O3) are allotropes of oxygen.
For example, phosphorous occurs in three forms--white, red, and black. White phosphorous is poisonous and very reactive, red phosphorous is not poisonous and it is only moderately reactive, and black phosphorous is nearly inert.
Rhombic and monoclinic sulfur are allotropes.
Seperate posts are there for each chapter.
---------------------------------
IIT JEE Syllabus NON-METALS
Isolation/preparation and properties of the following non-metals:
Boron,
silicon,
nitrogen,
phosphorus,
oxygen,
sulphur and
halogens;
Properties of allotropes of
carbon (only diamond and graphite),
phosphorus and
sulphur.
Boron (B)
Z = 5, 1s²2s²2px¹
Boron belongs to 13th group.
Method of obtaining Boron
By the reduction of boric oxide by an electropositive metal like magnesium.
silicon (Si) -
Atomic Number is 14. 1s²2s²2p^63s²3p²
Method of obtaining Silicon: Heating finely divided silica with magnesium powder.
Sulphur (S)
Partial combustion of Hydrogen sulphide produce sulphur.
Halogens
Flourine (F), Chlorine (Cl), Bromine (Br), Iodine (I).
Chlorine is yellow green gas
Bromine is reddish brown liquid
Iodine is steel grey solid
Allotrope
• Allotropes are elements that can exist in two or more different physical forms
• Diamond, graphite and buckminster fullerine are allotropes of carbon.
• The allotropes of carbon are all the element carbon. The type of carbon is determined from the bonding that occurs.
The carbon atoms in graphite are arranged in flat sheets that slide easily over each other, while the atoms in diamond are bonded in a complex, honeycombed structure that makes the solid much harder.
Atmospheric oxygen (O2) and ozone (O3) are allotropes of oxygen.
For example, phosphorous occurs in three forms--white, red, and black. White phosphorous is poisonous and very reactive, red phosphorous is not poisonous and it is only moderately reactive, and black phosphorous is nearly inert.
Rhombic and monoclinic sulfur are allotropes.
IIT JEE Ch.14. COMPOUNDS OF METALS - Core Points for Revision
JEE Syllabus
Preparation and properties of the following compounds:
Oxides,
peroxides,
hydroxides,
carbonates,
bicarbonates,
chlorides and
sulphates of
sodium,
potassium,
magnesium and
calcium;
Aluminium: alumina, aluminium chloride and alums;
---------------
Sodium Oxide
Sodium oxide has formula Na2O.
It is also called sodium(I) oxide, disodium oxide, sodium monoxide, and soda.
Sodium peroxide
A nearly white compound (Na 2 O 2 ), having vigorous oxidizing properties, and used in bleaching mechanical paper pulps and as a final stage in the bleaching of chemical paper pulps in some multi-stage bleaching sequences.
Sodium hydroxide
sodium hydroxide chemical compound, NaOH, is a white crystalline substance that readily absorbs carbon dioxide and moisture from the air.
Sodium carbonate
Sodium carbonate exists as anhydrous (Na2CO3) and also as hydrated salt. The decahydrated salt (Na2CO3.10H2O) is known as washing soda while the anhydrous salt is called soda ash.
Sodium Bicarbonate NaHCO-3
Sodium Bicarbonate, commonly called baking soda, is a white odourless, crystalline solid, completely soluble in water but slightly soluble in ethanol. It is the mildest of all sodium alkalis.
Sodium chloride
Sodium chloride (NaCl) or common salt is an ionic crystal consisting of equal numbers of sodium and chlorine atoms and is an essential component in the human diet, being found in blood sweat and tears.
Sodium sulphate
FORMULA Na2SO4
Sodium sulfate is a white, orthorhombic crystalline solid at room temperatures ( a monoclinic structure at > 100 C, a hexagonal structure at > 250C).
Potassium Oxide
Formula as commonly written: K2O
Physical properties
• Colour: yellowish white to grey
• Appearance: crystalline solid
Potassium peroxide
K2O2
Potassium hydroxide
Potassium Hydroxide, commonly called caustic potash with formula KOH, is a caustic compound of strong alkaline chemical dissolving readily in water, giving off much heat and forming a caustic solution.
Potassium carbonate
Potassium carbonate is a white salt, soluble in water (insoluble in alcohol), which forms a strongly alkaline solution.
Potassium bicarbonate
Potassium bicarbonate (also known as potassium hydrogen carbonate or potassium acid carbonate), is a colorless, odorless, slightly basic, salty substance.
Potassium chloride - KCl
Potassium chloride is also commonly known as "Muriate of Potash".
Potassium sulphate
Potassium sulfate (K2SO4) (also known as potash of sulfur) is a non-flammable white crystalline salt which is soluble in water. The chemical is commonly used in fertilizers, providing both potassium and sulfur.
Magnesium Oxide
Magnesium oxide
Roasting either magnesium carbonate or magnesium hydroxide produces the oxygen compound magnesium oxide, commonly called magnesia, MgO, a white solid used in the manufacture of high-temperature refractory bricks, electrical and thermal insulators, cements, fertilizer, rubber, and plastics. It is used medically as a laxative.
Magnesium peroxide
Magnesium peroxide is a fine powder peroxide with a white to white-off color.
Magnesium hydroxide
Magnesium hydroxide, Mg(OH)2, is a white powder produced in large quantities from seawater by the addition of milk of lime (calcium hydroxide).
Magnesium carbonate
Magnesium carbonate, MgCO3, occurs in nature as the mineral magnesite and is an important source of elemental magnesium. It can be produced artificially by the action of carbon dioxide on a variety of magnesium compounds.
Magnesium bicarbonate
Mg(HCO3)2
Magnesium bicarbonate + Lime → Calcium carbonate + Magnesium carbonate + Water
Mg(HCO3)2 + Ca(OH)2 → CaCO3 + MgCO3 + 2H2O
Magnesium chloride
The action of hydrochloric acid on magnesium hydroxide produces magnesium chloride, MgCl2, a colourless, deliquescent (water-absorbing) substance employed in magnesium metal production, in the manufacture of a cement for heavy-duty flooring, and as an additive in textile manufacture.
Magnesium sulphate
Magnesium sulfate, MgSO-4, is a colourless, crystalline substance formed by the reaction of magnesium hydroxide with sulfur dioxide and air.
Calcium Oxide CaO
Calcium oxide is commonly known as quicklime, and is a material of primary importance in the building industry.
Calcium peroxide
Calcium peroxide (CaO2) is a solid peroxide with a white or yellowish color.
Calcium hydroxide
Calcium hydroxide (Ca(OH)-2)
Calcium hydroxide in solid powdered form is called slaked lime. A suspension of slaked lime in water is called milk of lime.
Calcium carbonate CaCO3
Calcium carbonate occurs abundantly as dolomite, MgCO3.CaCO3, a mixture of calcium and magnesium carbonates.
Calcium bicarbonate
Calcium bicarbonate (Ca(HCO3)2), also called calcium hydrogen carbonate, does not refer to a known solid compound; it “exists” only in a solution containing the ions calcium Ca^2+, dissolved carbon dioxide CO2, bicarbonate HCO3–, and carbonate CO3^2–.
Calcium chloride
Calcium chloride (CaCl2) is an ionic compound of calcium and chlorine.
It can be produced directly from limestone, but large amounts are also produced as a by-product of the Solvay process.
Calcium sulphate (CaSO4)
Calcium sulphate can be obtained by heating gypsum above 200°C.
Compounds of Aluminium: alumina, aluminium chloride and alums;
Aluminium oxide(Al2O3), also known as alumina, is the main component of bauxite, the principal ore of aluminium.
Aluminium chloride (AlCl3) is manufactured on a large scale by the exothermic reaction of aluminium metal with chlorine or hydrogen chloride.
Alum is a salt that in chemistry is a combination of an alkali metal, such as sodium, potassium, or ammonium and a trivalent metal, such as aluminum, iron, or chromium.
The most common form, potassium aluminum sulfate, or potash alum, is one form that has been used in food processing.
Preparation and properties of the following compounds:
Oxides,
peroxides,
hydroxides,
carbonates,
bicarbonates,
chlorides and
sulphates of
sodium,
potassium,
magnesium and
calcium;
Aluminium: alumina, aluminium chloride and alums;
---------------
Sodium Oxide
Sodium oxide has formula Na2O.
It is also called sodium(I) oxide, disodium oxide, sodium monoxide, and soda.
Sodium peroxide
A nearly white compound (Na 2 O 2 ), having vigorous oxidizing properties, and used in bleaching mechanical paper pulps and as a final stage in the bleaching of chemical paper pulps in some multi-stage bleaching sequences.
Sodium hydroxide
sodium hydroxide chemical compound, NaOH, is a white crystalline substance that readily absorbs carbon dioxide and moisture from the air.
Sodium carbonate
Sodium carbonate exists as anhydrous (Na2CO3) and also as hydrated salt. The decahydrated salt (Na2CO3.10H2O) is known as washing soda while the anhydrous salt is called soda ash.
Sodium Bicarbonate NaHCO-3
Sodium Bicarbonate, commonly called baking soda, is a white odourless, crystalline solid, completely soluble in water but slightly soluble in ethanol. It is the mildest of all sodium alkalis.
Sodium chloride
Sodium chloride (NaCl) or common salt is an ionic crystal consisting of equal numbers of sodium and chlorine atoms and is an essential component in the human diet, being found in blood sweat and tears.
Sodium sulphate
FORMULA Na2SO4
Sodium sulfate is a white, orthorhombic crystalline solid at room temperatures ( a monoclinic structure at > 100 C, a hexagonal structure at > 250C).
Potassium Oxide
Formula as commonly written: K2O
Physical properties
• Colour: yellowish white to grey
• Appearance: crystalline solid
Potassium peroxide
K2O2
Potassium hydroxide
Potassium Hydroxide, commonly called caustic potash with formula KOH, is a caustic compound of strong alkaline chemical dissolving readily in water, giving off much heat and forming a caustic solution.
Potassium carbonate
Potassium carbonate is a white salt, soluble in water (insoluble in alcohol), which forms a strongly alkaline solution.
Potassium bicarbonate
Potassium bicarbonate (also known as potassium hydrogen carbonate or potassium acid carbonate), is a colorless, odorless, slightly basic, salty substance.
Potassium chloride - KCl
Potassium chloride is also commonly known as "Muriate of Potash".
Potassium sulphate
Potassium sulfate (K2SO4) (also known as potash of sulfur) is a non-flammable white crystalline salt which is soluble in water. The chemical is commonly used in fertilizers, providing both potassium and sulfur.
Magnesium Oxide
Magnesium oxide
Roasting either magnesium carbonate or magnesium hydroxide produces the oxygen compound magnesium oxide, commonly called magnesia, MgO, a white solid used in the manufacture of high-temperature refractory bricks, electrical and thermal insulators, cements, fertilizer, rubber, and plastics. It is used medically as a laxative.
Magnesium peroxide
Magnesium peroxide is a fine powder peroxide with a white to white-off color.
Magnesium hydroxide
Magnesium hydroxide, Mg(OH)2, is a white powder produced in large quantities from seawater by the addition of milk of lime (calcium hydroxide).
Magnesium carbonate
Magnesium carbonate, MgCO3, occurs in nature as the mineral magnesite and is an important source of elemental magnesium. It can be produced artificially by the action of carbon dioxide on a variety of magnesium compounds.
Magnesium bicarbonate
Mg(HCO3)2
Magnesium bicarbonate + Lime → Calcium carbonate + Magnesium carbonate + Water
Mg(HCO3)2 + Ca(OH)2 → CaCO3 + MgCO3 + 2H2O
Magnesium chloride
The action of hydrochloric acid on magnesium hydroxide produces magnesium chloride, MgCl2, a colourless, deliquescent (water-absorbing) substance employed in magnesium metal production, in the manufacture of a cement for heavy-duty flooring, and as an additive in textile manufacture.
Magnesium sulphate
Magnesium sulfate, MgSO-4, is a colourless, crystalline substance formed by the reaction of magnesium hydroxide with sulfur dioxide and air.
Calcium Oxide CaO
Calcium oxide is commonly known as quicklime, and is a material of primary importance in the building industry.
Calcium peroxide
Calcium peroxide (CaO2) is a solid peroxide with a white or yellowish color.
Calcium hydroxide
Calcium hydroxide (Ca(OH)-2)
Calcium hydroxide in solid powdered form is called slaked lime. A suspension of slaked lime in water is called milk of lime.
Calcium carbonate CaCO3
Calcium carbonate occurs abundantly as dolomite, MgCO3.CaCO3, a mixture of calcium and magnesium carbonates.
Calcium bicarbonate
Calcium bicarbonate (Ca(HCO3)2), also called calcium hydrogen carbonate, does not refer to a known solid compound; it “exists” only in a solution containing the ions calcium Ca^2+, dissolved carbon dioxide CO2, bicarbonate HCO3–, and carbonate CO3^2–.
Calcium chloride
Calcium chloride (CaCl2) is an ionic compound of calcium and chlorine.
It can be produced directly from limestone, but large amounts are also produced as a by-product of the Solvay process.
Calcium sulphate (CaSO4)
Calcium sulphate can be obtained by heating gypsum above 200°C.
Compounds of Aluminium: alumina, aluminium chloride and alums;
Aluminium oxide(Al2O3), also known as alumina, is the main component of bauxite, the principal ore of aluminium.
Aluminium chloride (AlCl3) is manufactured on a large scale by the exothermic reaction of aluminium metal with chlorine or hydrogen chloride.
Alum is a salt that in chemistry is a combination of an alkali metal, such as sodium, potassium, or ammonium and a trivalent metal, such as aluminum, iron, or chromium.
The most common form, potassium aluminum sulfate, or potash alum, is one form that has been used in food processing.
IIT JEE Ch.15. COMPOUNDS OF NONMETALS - Core Points for Revision
Syllabus
Preparation and properties of the following compounds:
Carbon: oxides and oxyacid (carbonic acid);
Silicon: silicones, silicates and silicon carbide;
Nitrogen: oxides, oxyacids and ammonia;
Phosphorus: oxides, oxyacids (phosphorus acid, phosphoric acid) and phosphine;
Oxygen: ozone and hydrogen peroxide;
Sulphur: hydrogen sulphide, oxides, sulphurous acid, sulphuric acid and sodium thiosulphate;
Halogens: hydrohalic acids, oxides and oxyacids of chlorine, bleaching powder; Xenon fluorides;
Fertilizers: commercially available (common) NPK type.
------------------------
Carbon: oxides and oxyacid (carbonic acid);
Carbon Monoxide CO
Carbon Dioxide CO2
Carbonic acid
Silicon: silicones, silicates and silicon carbide;
silicon dioxide SiO2
Nitrogen: oxides, oxyacids and ammonia;
Ammonia NH3
Phosphorus: oxides, oxyacids (phosphorus acid, phosphoric acid) and phosphine;
Oxygen: ozone and hydrogen peroxide;
Ozone O3
Hydrogen Peroxide H2O2
Sulphur: hydrogen sulphide, oxides, sulphurous acid, sulphuric acid and sodium thiosulphate;
H2S
SO2
H2SO4
Halogens: hydrohalic acids, oxides and oxyacids of chlorine, bleaching powder; Xenon fluorides;
HCl
HI
XeF2, XeF4
Fertilizers: commercially available (common) NPK type.
This chapter's revision points need to maintained topic wise only.
Preparation and properties of the following compounds:
Carbon: oxides and oxyacid (carbonic acid);
Silicon: silicones, silicates and silicon carbide;
Nitrogen: oxides, oxyacids and ammonia;
Phosphorus: oxides, oxyacids (phosphorus acid, phosphoric acid) and phosphine;
Oxygen: ozone and hydrogen peroxide;
Sulphur: hydrogen sulphide, oxides, sulphurous acid, sulphuric acid and sodium thiosulphate;
Halogens: hydrohalic acids, oxides and oxyacids of chlorine, bleaching powder; Xenon fluorides;
Fertilizers: commercially available (common) NPK type.
------------------------
Carbon: oxides and oxyacid (carbonic acid);
Carbon Monoxide CO
Carbon Dioxide CO2
Carbonic acid
Silicon: silicones, silicates and silicon carbide;
silicon dioxide SiO2
Nitrogen: oxides, oxyacids and ammonia;
Ammonia NH3
Phosphorus: oxides, oxyacids (phosphorus acid, phosphoric acid) and phosphine;
Oxygen: ozone and hydrogen peroxide;
Ozone O3
Hydrogen Peroxide H2O2
Sulphur: hydrogen sulphide, oxides, sulphurous acid, sulphuric acid and sodium thiosulphate;
H2S
SO2
H2SO4
Halogens: hydrohalic acids, oxides and oxyacids of chlorine, bleaching powder; Xenon fluorides;
HCl
HI
XeF2, XeF4
Fertilizers: commercially available (common) NPK type.
This chapter's revision points need to maintained topic wise only.
Ch.16.Transition Elements - core Points for Revision
Syllabus
Transition elements (3d series):
Definition, general characteristics, oxidation states and their stabilities, colour (excluding the details of electronic transitions) and calculation of spin-only magnetic moment;
Coordination compounds: nomenclature of mononuclear coordination compounds, cis-trans and ionisation isomerisms, hybridization and geometries of mononuclear coordination compounds (linear, tetrahedral, square planar and octahedral).
---------------
A transition element may be defined as an element which in its elementary form or in at least one of its oxidation states, possesses partially filled d orbitals in its penultimate shell.
Three series of elements are formed by filling the 3d, 4d, and 5d shells by electrons.
First series or 3d series: Scandium to Zinc
Second series or 4d series: Yitrium to cadmium
Third series or 5d series: Lanthanum to hafnium to mercury
In JEE syllabus only 3d series is there.
The ten elements from Scandium to Zinc form the first transition metal series. They closely resemble each other and are hard, dense, shiny metals with high melting and boiling points.
oxidation states
Common oxidation states are +2 and +3, with the +2 state more common towards the end. The higher oxidation states are shown in compounds with electronegative elements like O, Cl or F (e.g. Cr2O7^2- [+6], MnO4^- [+7]).
Variable oxidation state is found because of the small difference in energy between the 3d and 4s sub-shells. This allows varying numbers of electrons to be used in bonding. When forming ions transition metals lose electrons from the 4s sub-shell before the 3d.
Catalytic Action
The ability of transition metals to exist in various oxidation states makes them important industrial and biological catalysts.
Coordination compounds are a special class of compounds in which the centgral metal atom is surrounded by ions or molecules beyond their valency.
There are also referred to as coordination complexes or complexes.
Haemoglobin, Chlrophyll, and vitamin B-12 are coordinatio compounds of iron, magnesium and cobalt respectively.
The interesting thing of coordination compound is that these are formed from apparently saturated molecules capable of independent existence.
Transition elements (3d series):
Definition, general characteristics, oxidation states and their stabilities, colour (excluding the details of electronic transitions) and calculation of spin-only magnetic moment;
Coordination compounds: nomenclature of mononuclear coordination compounds, cis-trans and ionisation isomerisms, hybridization and geometries of mononuclear coordination compounds (linear, tetrahedral, square planar and octahedral).
---------------
A transition element may be defined as an element which in its elementary form or in at least one of its oxidation states, possesses partially filled d orbitals in its penultimate shell.
Three series of elements are formed by filling the 3d, 4d, and 5d shells by electrons.
First series or 3d series: Scandium to Zinc
Second series or 4d series: Yitrium to cadmium
Third series or 5d series: Lanthanum to hafnium to mercury
In JEE syllabus only 3d series is there.
The ten elements from Scandium to Zinc form the first transition metal series. They closely resemble each other and are hard, dense, shiny metals with high melting and boiling points.
oxidation states
Common oxidation states are +2 and +3, with the +2 state more common towards the end. The higher oxidation states are shown in compounds with electronegative elements like O, Cl or F (e.g. Cr2O7^2- [+6], MnO4^- [+7]).
Variable oxidation state is found because of the small difference in energy between the 3d and 4s sub-shells. This allows varying numbers of electrons to be used in bonding. When forming ions transition metals lose electrons from the 4s sub-shell before the 3d.
Catalytic Action
The ability of transition metals to exist in various oxidation states makes them important industrial and biological catalysts.
Coordination compounds are a special class of compounds in which the centgral metal atom is surrounded by ions or molecules beyond their valency.
There are also referred to as coordination complexes or complexes.
Haemoglobin, Chlrophyll, and vitamin B-12 are coordinatio compounds of iron, magnesium and cobalt respectively.
The interesting thing of coordination compound is that these are formed from apparently saturated molecules capable of independent existence.
Ch.17. Ores/Minerals and Extractive Metallury - Core Points for Revision
Syllabus
Ores and minerals: Commonly occurring ores and minerals of
iron,
copper,
tin,
lead,
magnesium,
aluminium,
zinc and
silver.
Extractive metallurgy: Chemical principles and reactions only (industrial details excluded);
Carbon reduction method (iron and tin);
Self reduction method (copper and lead);
Electrolytic reduction method (magnesium and aluminium);
Cyanide process (silver and gold).
Ores and minerals of iron
Magnetite
Haematite
Limonite
Iron Pyrites
Copper Pyrites
Haematite is the principal ore.
Ores and minerals of Tin
Tin stone
Ores and minerals of Copper
Copper pyrites
Malachanite
Cuprite or ruby copper
Azurite
Copper glance
Minerals of Lead
Galena
Cerussite
Anglesite
Wulfenite
Stolzite
Minerals of Magnesium
Magnesite
Carnallite
Kiesserite
Schonite
Dolomite
Epsomite
kainite
Minerals of Alumium
Corundum
Diaspore
Bauxite
Cryolite
Feldspar, Mica, Kaolinite
Alunite or Alumstone
Turquoise
Aluminates of Magensium, Iron and Manganese
Minerals of Silver
Argentite
Pyrargarite
Proustite
Horn Silver
Minerals of Zinc
(from X book by Viraf Dalal)
Zincite
Calamine
Zinc Blende
Minerals of Gold
Mainly native gold
Nagyagite
Calaverite
Sylvanite
Krennerite
Fe
The reduction of the ore
At the high temperature at the bottom of the furnace, carbon dioxide reacts with carbon to produce carbon monoxide.
It is the carbon monoxide which is the main reducing agent in the furnace.
Extraction of Tin
The ore is tin stone that contains 10% of the metal as SnO2.
SnO2 + 2C = Sn + 2CO
The moltenmetal is collected from the bottom of the blast furnace.
The metal may be purified elctrolytically
Copper
The concentrated ore is heated strongly with silicon dioxide (silica) and air or oxygen in a furnace or series of furnaces.
Electrolysis of magnesium
• Dolomite and seawater is precipitated
as insoluble magnesium hydroxide
Mg(OH)2 which is subsequently treated
with HCl to give MgCl2.
• MgCl2 is fed into electrolysis cell to
produce Mg metal at cathode and Cl2
at anode.
Conversion of the aluminium oxide into aluminium by electrolysis
The aluminium oxide is electrolysed in solution in molten cryolite, Na3AlF6. Cryolite is another aluminium ore, but is rare and expensive, and most is now made chemically.
Gold
It is now the most important and widely used process for extracting gold from ores.
The ore is first finely ground and concentrated by flotation.
To remove certain impurities, it may be roasted.
It is then mixed with a dilute solution of sodium cyanide (or potassium or calcium cyanide) while air is bubbled through it.
Soluble aurocyanide complex ion, Au(CN)-2^-1 is formed .
Silver, usually present as an impurity, also forms a similar soluble ion.
Ores and minerals: Commonly occurring ores and minerals of
iron,
copper,
tin,
lead,
magnesium,
aluminium,
zinc and
silver.
Extractive metallurgy: Chemical principles and reactions only (industrial details excluded);
Carbon reduction method (iron and tin);
Self reduction method (copper and lead);
Electrolytic reduction method (magnesium and aluminium);
Cyanide process (silver and gold).
Ores and minerals of iron
Magnetite
Haematite
Limonite
Iron Pyrites
Copper Pyrites
Haematite is the principal ore.
Ores and minerals of Tin
Tin stone
Ores and minerals of Copper
Copper pyrites
Malachanite
Cuprite or ruby copper
Azurite
Copper glance
Minerals of Lead
Galena
Cerussite
Anglesite
Wulfenite
Stolzite
Minerals of Magnesium
Magnesite
Carnallite
Kiesserite
Schonite
Dolomite
Epsomite
kainite
Minerals of Alumium
Corundum
Diaspore
Bauxite
Cryolite
Feldspar, Mica, Kaolinite
Alunite or Alumstone
Turquoise
Aluminates of Magensium, Iron and Manganese
Minerals of Silver
Argentite
Pyrargarite
Proustite
Horn Silver
Minerals of Zinc
(from X book by Viraf Dalal)
Zincite
Calamine
Zinc Blende
Minerals of Gold
Mainly native gold
Nagyagite
Calaverite
Sylvanite
Krennerite
Fe
The reduction of the ore
At the high temperature at the bottom of the furnace, carbon dioxide reacts with carbon to produce carbon monoxide.
It is the carbon monoxide which is the main reducing agent in the furnace.
Extraction of Tin
The ore is tin stone that contains 10% of the metal as SnO2.
SnO2 + 2C = Sn + 2CO
The moltenmetal is collected from the bottom of the blast furnace.
The metal may be purified elctrolytically
Copper
The concentrated ore is heated strongly with silicon dioxide (silica) and air or oxygen in a furnace or series of furnaces.
Electrolysis of magnesium
• Dolomite and seawater is precipitated
as insoluble magnesium hydroxide
Mg(OH)2 which is subsequently treated
with HCl to give MgCl2.
• MgCl2 is fed into electrolysis cell to
produce Mg metal at cathode and Cl2
at anode.
Conversion of the aluminium oxide into aluminium by electrolysis
The aluminium oxide is electrolysed in solution in molten cryolite, Na3AlF6. Cryolite is another aluminium ore, but is rare and expensive, and most is now made chemically.
Gold
It is now the most important and widely used process for extracting gold from ores.
The ore is first finely ground and concentrated by flotation.
To remove certain impurities, it may be roasted.
It is then mixed with a dilute solution of sodium cyanide (or potassium or calcium cyanide) while air is bubbled through it.
Soluble aurocyanide complex ion, Au(CN)-2^-1 is formed .
Silver, usually present as an impurity, also forms a similar soluble ion.
Langganan:
Postingan (Atom)