Tuesday, March 15, 2011

Chemical Reactions and Temperature Investigation

Today we had a Chemical Reaction and Heat Lab Investigation where we investigated how temperature varies chemical reactions. The materials needed for this lab investigation were a 600mL beaker, a stirring rod, metal tongs/clamps, Vernier software, temperature probe, ring stand, graduated cylinder, 3 alka-seltzer tablets, stopwatch, hot plate, ice cubes, laptop, and 665mL of water.

My hypothesis was: If increased temperature increases the reaction rate, then the Hot Test will have the quickest dissolve time because it has the highest temperature. In order to find out if this hypothesis would be supported or not, I had to complete the three tests: Hot, Room Temperature, and Cold. Each test involved filling the beaker up with water, getting it to a certain temperature, and dissolving the tablets in the water. The difference was that the Hot test used a hot plate and needed to go up to 50 degrees Celsius, the Room Temp. test just needed to be regular water, and the Cold test needed ice cubes.

Our results are shown in the chart below:

The proved our hypothesis to be true because the Hot test ended up having the shortest dissolve time (23 seconds). Room Temperature was only 16 seconds behind, and Cold was 97 seconds behind. Basically, hotter temperatures will tend to quicken the rates of chemical reactions (especially when concerning the dissolving of something).

Below are diagrams of how the beaker looked for each test.
This was my diagram for the Room Temperature test. Bubbles were flying from the alka-seltzer tablet (as shown in diagram). In fact, the bubbles were coming so rapidly that the tablet was spinning round and round until it settled back at the top to dissovle into foam.

Then there was the Hot test, immediately after the tablet was dropped into the heated water it started to fizz. All around the tablet was bubbly foam, unlike the Room Temp. test, bubbles did not start spurting out until a little later. It mainly just fizzed.

Last was the Cold test. There were bubbles during the Cold test, but they were rather large and came very slowly. After about a minut the tablet started to really fizz and then it started looking like the Room Temperature beaker.

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