Test Tube Science: Plop Plop Fizz Fizz

Materials:
   -Two test tubes
   -10 mL hot water
   -10 mL cold water
   -One tablet of AlkaSeltzer

Background:
The rate at which a reaction progresses depends on the temperature of the reaction.  This experiment lets observe this first hand.

Directions:
Fill one test tube with hottest tap water available.  Fill another with cold, cold water.  Break an Alka Seltzer tablet into small pieces.  Drop carefully into each test tube.  See which temperature water makes the most popping and fizzing.