Heating Chemical Reactions

4.0 based on 86 ratings

Updated on Feb 05, 2012

Grade Level: 7th - 9th; Type: Chemistry


Heat and cold can strongly affect the speed of a chemical reaction. This science project will determine the effect heat has on the reaction between a seltzer tablet and a glass of water.

Research Question:

What effect does heat have on a chemical reaction?

Some chemical reactions, such as rusting, take a long time. Others, such as burning, take a very short amount of time. How does heat affect the rate of the reaction? This science project will allow you test how heat affects a specific chemical reaction – between seltzer tablets and water.


  • Water
  • 2 identical cups
  • Ice
  • Seltzer tablets
  • Thermometer (optional)

Experimental Procedure:

  1. Pour cold water into one cup until it is about 2/3 full.
  2. Add ice to the water so that it reaches the top of the cup.
  3. Wait until the ice melts completely, about five to ten minutes. The result should be extremely cold water.
  4. Fill the second cup to the top with very hot tap water.
  5. Drop one seltzer tablet into each cup, making sure to do so simultaneously.
  6. Observe the chemical reaction that follows.
  7. How long does it take for the chemical reaction in each cup to complete? Record your data in a simple table, such as the one below.

Consider extensions for this experiment. For example, you might use a thermometer to measure the temperatures of various cups of water and make a line graph showing the relationship between the water temperature in each cup and the time it takes for the reaction to complete. Can you determine what the relationship between the two variables is? Can you predict how long the reaction will take in water of any given temperature?

Terms/Concepts: Chemical reaction; How do seltzer tablets work?; What does heat do to molecules?


  • Easy Genius Science Projects with Chemistry, by Robert Gardener. Page 53.
Keren Perles has worked as an educational writer, editor, teacher, and tutor of all ages. Her experience spans the subject areas, from science and math, to English and the Hebrew language.

How likely are you to recommend Education.com to your friends and colleagues?

Not at all likely
Extremely likely