Experiment 7.4 – Chemistry Form 4 Chapter 7 (Rate of Reaction)


Experiment 7.4:
Aim: To investigate the effect of catalyst on the rate of reaction.

Problem statement: How does the presence of catalyst affect the rate of reaction?

Hypothesis: Presence of catalyst increases the rate of reaction.

Variables:
(a) Manipulated : Presence of catalyst

(b) Responding : Rate of reaction

(c) Fixed : Mass of manganese(IV) oxide, MnO2, temperature and volume of hydrogen peroxide solution, H2O2

Materials: 20-volume hydrogen peroxide solution, H22O2, manganese(IV) oxide powder, MnO2 and distilled water

Apparatus: 10 cm3 measuring cylinder, test tubes, test tube rack, glowing wooden splinter, filter funnel, filter paper, 150 cm3 beaker, spatula and electronic balance


Procedure:
1. Label two test tubes as I and II.

2. Put 5 cm3 hydrogen peroxide solution, H2O2 into test tube I and test tube II separately.

3. Place the two test tubes in the test tube rack.

4. Add 0.5 g manganese(IV) oxide powder, MnO2 into test tube II. Place a glowing wooden splinter into the mouth of both test tubes quickly.

5. Observe the changes that occur to the wooden splinter and record your observations.

Conclusion:
Is the hypothesis acceptable? What is the conclusion of this experiment?

Discussion:
1. What are the changes observed and measured in this experiment?

2. Explain how the observation in (1) can assure your hypothesis.


Answer:
Discussion:
1. The release of oxygen gas can rekindle a glowing wooden splinter. The time for oxygen gas to rekindle a glowing wooden splinter.

2. The faster the glowing wooden splinter is rekindled, the higher the rate of reaction.