Does Temperature Affect Chemical Reaction Time?

Today’s lab was all about how things dissolve in water. In the lab, we had two four pack alka seltzer tablets to use for the lab. The tablets were previously used to calm an upset stomach.  What would happen when you put in in your stomach. How fast would it react? Can temperature change the rate of reaction? That’s what this lab was all about.

Here is the equation we used:

NaHCO3 + C6H8CO7 =H2O + CO2 + NaC6H5O7

Materials:

500mL Beaker

1 Graduated Cylinder

Logger Pro Interface

Temperature Probe

Watch or Clock (iPod)

Hot Plate

Ice Cubes

Camera

TEST 1:

In this test, we had the beaker boiling until it reached 50.0 C. It took awhile becase for some reason the temperature spiked up and went to 59.0 C. We waited a bit for it to cool down. After it reached the temperature we put the tablet in. It bubbled and fizzed. It really jumped and moved around. It rose to the surface once half of it was dissolved.  When we analyzed it from the bottom we noticed that there were tiny bubbles keeping it from touching the bottom of the beaker. It took 20.7 seconds for it to dissolve completely.

TEST 2:

In this test, we got more accustom to using the tablets. We learned that the info could be messed up unless you time the clock at the right moment when the tablet hits the water. The next test was room temperature water. We discussed and noticed that room temperature does mess up the test. Room temperature is whatever temperature the room is. The room could be 70.0 C or 20.0 C and that would be considered “room temperature”. We continued the experiment anyway. The temperature of the water (and room) was 37.1 C. We then dropped the tablet in. It fizzed and bubbles and was moving around a bit. It rose to the top after 13.5 seconds. It dissolved completely when 22. seconds past. A bit slower than the 50.0 C, but it seems normal. It the water is hotter than it should dissolve faster.

TEST 3:

This test was my favorite because it had to do with ice. The tablet had to dissolve in icewater. It took a while for one of my lab partners to get the ice, so the rest of us talked about how the test was going to far. We learned that temperature does impact the rate is dissolves and it this is true then it should take a while for the third tablet to dissolve. We were right. When we put the tablet in it literally took 3 minutes and 27 seconds for it to dissolve. It was 2.0 C in the water. We then came to the conclusion that you shouldn’t drink cold water if you stomach hurts.

TEST 4: Our Bonus Test :)

This test was our favorite, because we got to use any temperature we wanted! What we decided to do is try to get the water as hot as we could. The temperature ended up being 100.0 C. Owch! Talk about hot! We put the tablet in and it fizzed like crazy! More like the water was eating it though. It looked like the water was taking bites out of it. It took 20.7 seconds for it to dissolve. We found it weird because it was the same amount of seconds it took for the 50.0 C tablet to dissolve. Maybe anything over that temperature does not affect it that much?

From that test, I conclude that certain temperatures does vary the results of how fast a chemicals reaction can be, but it must be drastic temperatures. It it’s 50.0 C and 60.0 it might be a shortened reaction time by a couple of seconds, but not that much.

Here are my sketches: