1. In the first demonstration, a 2 liter bottle that was coated with ethanol, or CH3CH2OH + O2. Then the cap was taken off the bottle and a lighter was held in front of it. The bottle flew backwards off the table it was on. Blue fire danced on the bottle and on the table for a couple of seconds. The CH3CH2OH + O2 turned into CO2 + H2O with the help of a catalyst, or in this case, the fire from the lighter. This equation was not balanced, so certain elements were lost in this process. When the fire was introduced, the atoms rearranged themselves. Both of the products, CO2 + H2O, formed covalent bonds. So, they wanted to find each other and share electrons to meet the octet rule. O2 is a diatomic molecule, so it was already pretty stable, but by bonding with the carbon it was more stable. The hydrogen atoms and oxygen met the octet rule so they were happier together than alone. So, after the flame was introduced, the product rearranged itself to be as happy as possible. This chemical reaction is an example of combustion.
This is the bottle being lit on fire and flying backwards.
2. In this demonstration, the baking soda and vinegar were mixed and they bubbled up a little bit and then the gas was trapped by a hand. Two candles were lit and then the gas was poured over each candle and the fire went out. This is because the reactants, acetic acid and sodium bicarbonate, created a gas, CO2. That is carbon dioxide and carbon dioxide takes away fuel from a fire. That means that CO2 is not reactive with heat, so it put the fire out. The chemical equation was:
3. Pure zinc was added to hydrochloric acid (HCl) and I thought that it would create ZnHCl and make a homogeneous mixture. Actually, when the zinc was added to the hydrochloric acid, it started to bubble and turned the liquid a little bit gray. Then the fire was introduced and and the liquid was on fire for a few seconds. The zinc bubbled and completely dissolved and the mixture turned completely gray. The mixture was warm, The bubbles were the hydrogen that was released when the zinc and chlorine bonded. So, the product turned out to be H + ZnCl. The Zn broke the bond between the H and Cl and bonded with the Cl. This is an example of single replacement.
4. This demonstration was quite interesting because it was done (accidentally) without an ingredient twice. Potassium iodide was poured in hydrogen peroxide with food coloring in it. It exploded everywhere. This happened one more time, minus the food coloring. A gas floated off of each explosion. On the third demonstration, dish soap was added. It trapped the gas so a foam swirled around the graduated cylinder. It is also known as elephant toothpaste. The foam radiated heat. The gas the dish soap trapped was O2. The chemical formula was
H2O2 + KI --> H2O + O2 + KI. This represents synthesis. It doesn’t fit any category perfectly though, so it can also be double replacement.
This is the bottle being lit on fire and flying backwards.2. In this demonstration, the baking soda and vinegar were mixed and they bubbled up a little bit and then the gas was trapped by a hand. Two candles were lit and then the gas was poured over each candle and the fire went out. This is because the reactants, acetic acid and sodium bicarbonate, created a gas, CO2. That is carbon dioxide and carbon dioxide takes away fuel from a fire. That means that CO2 is not reactive with heat, so it put the fire out. The chemical equation was:
CH3COOH + NaHCO3 --> H2O + NaOCOCH3CO2
This is an example of an acid base chemical reaction. 3. Pure zinc was added to hydrochloric acid (HCl) and I thought that it would create ZnHCl and make a homogeneous mixture. Actually, when the zinc was added to the hydrochloric acid, it started to bubble and turned the liquid a little bit gray. Then the fire was introduced and and the liquid was on fire for a few seconds. The zinc bubbled and completely dissolved and the mixture turned completely gray. The mixture was warm, The bubbles were the hydrogen that was released when the zinc and chlorine bonded. So, the product turned out to be H + ZnCl. The Zn broke the bond between the H and Cl and bonded with the Cl. This is an example of single replacement.
4. This demonstration was quite interesting because it was done (accidentally) without an ingredient twice. Potassium iodide was poured in hydrogen peroxide with food coloring in it. It exploded everywhere. This happened one more time, minus the food coloring. A gas floated off of each explosion. On the third demonstration, dish soap was added. It trapped the gas so a foam swirled around the graduated cylinder. It is also known as elephant toothpaste. The foam radiated heat. The gas the dish soap trapped was O2. The chemical formula was
H2O2 + KI --> H2O + O2 + KI. This represents synthesis. It doesn’t fit any category perfectly though, so it can also be double replacement.
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