Lesson 3.1.5.4

3.1.5.4 Effect of concentration and pressure Quiz: AQA Chemistry, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.1.5.4, Effect of concentration and pressure: 20 multiple choice questions for the AQA Chemistry (7405), Unit 1: Physical chemistry, written with Revision Ninja.

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The 20 questions

  1. What happens to the collision frequency when reactant concentration is increased in solution?

    • Increases
    • Stays constant
    • Halves
    • Decreases

  2. What is the effect of increasing gas pressure on the collision frequency of molecules?

    • Decreases
    • Doubles
    • Stays constant
    • Increases

  3. Why does increasing concentration increase the rate of a reaction?

    • Lower activation energy
    • Higher particle density
    • Higher kinetic energy
    • Larger particle size

  4. How does changing reactant concentration affect the proportion of particles with energy above activation energy?

    • Increases proportion
    • Decreases proportion
    • Doubles proportion
    • No effect

  5. What property of a gas increases when a fixed mass is compressed at constant temperature?

    • Concentration
    • Particle speed
    • Mean kinetic energy
    • Activation energy

  6. How can the rate of reaction between calcium carbonate and hydrochloric acid be continuously monitored?

    • Solution colour
    • Solution pH
    • Mass loss
    • Flask temperature

  7. Which quantity is directly measured over time to follow the reaction between calcium carbonate and acid?

    • Solution temperature
    • Decreasing mass
    • Increasing pH
    • Chemical colour

  8. If doubling a reactant concentration doubles the reaction rate, what is the mathematical relationship between them?

    • Directly proportional
    • Exponentially related
    • Inversely proportional
    • Completely independent

  9. Halving the volume of a gas container at constant temperature has what effect on reaction rate?

    • It doubles
    • It remains constant
    • It halves
    • It quadruples

  10. Why does increasing the concentration of acid increase the rate of reaction with calcium carbonate?

    • Lower activation energy
    • Increased enthalpy change
    • Higher particle energy
    • More frequent collisions

  11. When investigating the effect of acid concentration on reaction rate, which variable must be kept constant?

    • Volume of gas
    • Solid surface area
    • Acid concentration
    • Reaction rate

  12. How does collision frequency at 2 atm compare to collision frequency at 1 atm at constant temperature?

    • Half as high
    • Exactly the same
    • Twice as high
    • Four times higher

  13. A solution of reactant at 2.00 mol dm-3 is compared with one at 0.50 mol dm-3. Roughly how many times more frequent are collisions at the higher concentration?

    • Four times
    • Eight times
    • Equal
    • Two times

  14. Why does increasing gas pressure at constant temperature leave average particle kinetic energy unchanged?

    • Temperature determines energy
    • Collisions consume energy
    • Pressure lowers mass
    • Volume increases energy

  15. What is the average rate of gas production when 60 cm³ of carbon dioxide forms in 30 seconds?

    • 1800 cm³ s⁻¹
    • 0.5 cm³ s⁻¹
    • 1 cm³ s⁻¹
    • 2 cm³ s⁻¹

  16. What effect does increasing the concentration of a liquid reactant have on activation energy?

    • No effect
    • Increases it
    • Eliminates it
    • Decreases it

  17. Why does compressing a gas increase collision frequency far more than compressing a liquid?

    • Gases compress easily
    • Liquids have volume
    • Gases move slower
    • Liquids lack mass

  18. Why does powdered calcium carbonate react faster with hydrochloric acid than large marble chips?

    • Higher kinetic energy
    • Greater surface area
    • Lower activation energy
    • Greater overall mass

  19. If doubling reactant B concentration does not change the reaction rate, what is the order regarding B?

    • Third order
    • First order
    • Zero order
    • Second order

  20. If doubling acid concentration halves the time taken for a reaction, what happens to the rate?

    • It halves
    • It stays constant
    • It quadruples
    • It doubles

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