Worksheet Chapter 7: Rate of Reaction

1. Fill in the blank: The minimum energy that colliding reactant particles must possess to initiate a chemical reaction is called ________ energy.

2. An experiment measuring oxygen gas evolution from hydrogen peroxide decomposition produced 48 cm³ of oxygen in 3 minutes. Calculate: (a) Total time in seconds. (b) The average rate of oxygen gas production in cm³/s.

3. Contrast the effects of raising reaction temperature versus adding a positive catalyst on an energy profile diagram using collision theory concepts.

4. Which of the following catalysts is correctly paired with its industrial process?

5. A student carries out an experiment reacting 2.0 g of marble chips with 50 cm³ of 0.5 mol dm⁻³ nitric acid. Suggest two adjustments to the experiment setup that would increase the rate of gas production.

6. Sodium thiosulfate solution reacts with dilute sulfuric acid to form a yellow precipitate of sulfur. The reaction equation is: Na₂S₂O₃ + H₂SO₄ → Na₂SO₄ + SO₂ + S + H₂O If the time taken for the black 'X' mark to disappear at 30°C is 50 seconds, calculate the value of 1/time (s⁻¹).

7. True or False: Adding a catalyst to a chemical reaction increases the total yield of the product formed at the end of the reaction.

8. In an experiment, 0.24 g of magnesium ribbon reacts completely with excess hydrochloric acid in 40 seconds to produce hydrogen gas. Calculate the average rate of reaction in gs.

9. Explain using collision theory how increasing the concentration of hydrochloric acid increases its rate of reaction with zinc granules.

10. True or False: Smaller pieces of reactant solids have a smaller total surface area than one large piece of the same total mass.