AP Chemistry Unit 5 practice questions: Kinetics
8 original multiple-choice questions on AP Chem Unit 5, kinetics. Answer each one in your browser and read the explanation, then review the key ideas below.
Question 1 of 8
When the concentration of reactant A is doubled, the reaction rate doubles. What is the order of the reaction with respect to A?
Question 2 of 8
How does a catalyst increase the rate of a reaction?
Question 3 of 8
A first-order reaction has a half-life of 10 minutes. What fraction of the reactant remains after 30 minutes?
Question 4 of 8
The rate law is rate = k[A]². What happens to the rate if [A] is tripled?
Question 5 of 8
Why does raising the temperature increase the rate of most reactions?
Question 6 of 8
What are the units of the rate constant k for a first-order reaction (time in seconds)?
Question 7 of 8
In a multistep reaction mechanism, the rate-determining step is
Question 8 of 8
For a reaction A → products, a plot of 1/[A] versus time is a straight line. What is the order in A?
Key ideas in Unit 5
- Rate laws are found by experiment, not from coefficients: rate = k[A]ᵐ[B]ⁿ.
- Integrated rate laws: straight [A] vs t means zero order, ln[A] vs t first order, 1/[A] vs t second order. First-order half-life is constant.
- Collision theory: particles must collide with enough energy (activation energy) and the right orientation.
- In a mechanism, the slowest step determines the rate law; intermediates are made and then used up.
- Catalysts lower the activation energy by providing a different pathway and are not consumed.
More AP Chem practice
← Unit 4: Chemical Reactions
Unit 6: Thermochemistry →
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