arrow_backBack to Study Resources

Quiz Chapter 7: Rate of Reaction

10 questions · Form 4 Chemistry Bab 7: Rate of Reaction

10 questions · plays in fullscreen

Full Question List & Answer Key

Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.

1. Which condition describes the optimum environment for Stage 2 of the Contact Process?

  1. 450°C, 1 atm, Vanadium(V) oxide catalyst
  2. 200°C, 200 atm, Iron catalyst
  3. 500°C, 200 atm, Nickel catalyst
  4. 100°C, 10 atm, Platinum catalyst
Show answer

Answer: A

The Contact Process uses 450°C, 1 atm pressure, and a Vanadium(V) oxide (V2O5) catalyst to convert SO2 to SO3.

2. According to collision theory, what two criteria are required for an effective collision?

  1. Low temperature and high pressure
  2. Correct collision orientation and energy equal to or greater than activation energy
  3. Presence of a catalyst and large surface area
  4. High concentration and small volume
Show answer

Answer: B

For a collision to be effective, particles must collide with correct orientation and sufficient energy (E ≥ Ea).

3. Why does increasing pressure increase the rate of reaction for gaseous reactants?

  1. It lowers the activation energy barrier
  2. It increases the temperature of the gas mixture
  3. It increases the number of gas particles per unit volume
  4. It changes the chemical nature of the gases
Show answer

Answer: C

Compressing gas into a smaller volume increases particle density per unit volume, raising collision frequency.

4. In a curve showing gas volume against time, what does a horizontal flat line indicate?

  1. The rate of reaction is at its maximum
  2. The reaction has completed because at least one reactant is fully used up
  3. The catalyst has been exhausted
  4. The activation energy has increased to infinity
Show answer

Answer: B

A horizontal flat gradient indicates that gas production has ceased because the limiting reactant is completely consumed.

5. Which curve in a rate experiment graph represents the fastest reaction rate?

  1. The curve with the steepest initial gradient
  2. The curve that takes the longest time to reach a flat line
  3. The curve with the lowest final volume
  4. The linear straight line along the x-axis
Show answer

Answer: A

The gradient of the curve represents the rate of reaction; a steeper initial curve means a higher initial reaction rate.

6. Which of the following defines the rate of reaction?

  1. The total energy absorbed during a chemical reaction
  2. The change in amount of reactant or product per unit time
  3. The total volume of gas produced at room condition
  4. The time taken for a chemical reaction to stop completely
Show answer

Answer: B

Rate of reaction measures the change in quantity of reactants or products over a specific period of time.

7. What is activation energy (Ea)?

  1. The heat released during a chemical reaction
  2. The energy level of the final products
  3. The minimum energy reactant particles must possess to react
  4. The total kinetic energy of all system particles
Show answer

Answer: C

Activation energy is the minimum barrier energy required by colliding particles to break bonds and initiate a reaction.

8. If 50 cm³ of carbon dioxide gas is collected in 20 seconds, what is the average rate of reaction?

  1. 2.5 cm³/s
  2. 0.4 cm³/s
  3. 1000 cm³/s
  4. 10.0 cm³/s
Show answer

Answer: A

Average rate = Total volume / Total time = 50 cm³ / 20 s = 2.5 cm³/s.

9. How does doubling the concentration of hydrochloric acid affect its reaction rate with magnesium ribbon?

  1. Decreases collision frequency per unit volume
  2. Increases the number of hydrogen ions per unit volume, raising effective collision frequency
  3. Lowers the activation energy of the reaction
  4. Increases the mass of magnesium consumed per second without changing collision rate
Show answer

Answer: B

Higher concentration increases particle count per unit volume, directly increasing total and effective collision frequencies.

10. Which reaction can have its rate determined by observing the formation of a yellow precipitate?

  1. Zinc and hydrochloric acid
  2. Sodium thiosulfate and sulfuric acid
  3. Calcium carbonate and nitric acid
  4. Copper(II) sulfate and sodium hydroxide
Show answer

Answer: B

The reaction between sodium thiosulfate and sulfuric acid produces sulfur, which forms a insoluble yellow precipitate.

Sponsored