Chemistry Lab Handout 19 “Reaction Rate”

Your Name: ___________________________________ Role:______________

Lab Partners: ________________Role:_____ ________________Role:_____

Problem: How does concentration, catalysts, temperature and stirring affect

the decomposition of hydrogen peroxide reaction rate?

Hypothesis: _______________________________________________________

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Materials: Vernier Lab Pro 3% Hydrogen Peroxide

0.5 M Potassium Iodide solution Vernier Gas Pressure Sensor

thermometer large test tube 2 10mL graduated cylinders

rubber stopper tubing Luer-lock connector

plastic pipet 1 L beaker warm water

Caution:

Procedure:

1. Obtain goggles and wear them for the entire lab.

2. Set up Lab Pro and Gas Pressure Sensor using the rubber stopper, tubing and

Luer-lock connector.

3. Add 4 mL of 3% Hydrogen Peroxide and 1 mL of distilled water to the large

test tube and stopper.

4. Place in the 1 L beaker filled with room temperature water and collect data.

5. Analyze the data by obtaining a line of best fit and determine the slope.

6. Repeat the experiment using 1 mL of 0.5 M KI instead of distilled water.

7. Repeat the experiment while gently shaking the test tube.

8. Repeat the experiment with only 2 mL of 3% Hydrogen Peroxide, 2 mL of

distilled water and 1 mL of 0.5 M KI.

9. Repeat the experiment using 1 mL of 0.5 M KI instead of distilled water but

use warm tap water in the 1 L beaker.

Data Table:

Trial	Temperature	reaction rate slope (kPa/s)
no catalyst
with catalyst
with catalyst, shaken
with catalyst and half concentration H2O2
with catalyst and warm water

Diagram:

Conclusion: _______________________________________________________

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Questions:

1. What is a catalyst?

2. How is the available activation energy affected by the warm water?

3. Write a balanced chemical equation to represent this reaction.

4. Draw a sketch of all of the molecules involved in the above reaction.

5. Determine the enthalpy change of the reaction. Show all of your work!

Remember that you have to add energy to break a bond (positive) and you

get energy back when a new bond is formed (negative).

6. Is the reaction endothermic or exothermic?