Unit 8: Chemical Reactivity
- What is the relationship between the activation energy and the rate constant of a reaction?
- A) Directly proportional
- B) Inversely proportional
- C) Unrelated
- D) Directly proportional to the square root
- Answer: B) Inversely proportional
- What type of reaction is represented by the general equation: A + B → C + D?
- A) Combination reaction
- B) Decomposition reaction
- C) Single displacement reaction
- D) Double displacement reaction
- Answer: D) Double displacement reaction
- What effect does increasing the concentration of a reactant have on the rate of a reaction if the reaction is second-order with respect to that reactant?
- A) The rate decreases
- B) The rate remains the same
- C) The rate increases linearly
- D) The rate increases quadratically
- Answer: D) The rate increases quadratically
- Which of the following is a true statement about a reversible reaction at equilibrium?
- A) The concentration of reactants is equal to the concentration of products.
- B) The forward and reverse reactions are occurring at the same rate.
- C) The reaction proceeds only in one direction.
- D) The rate of the forward reaction is greater than the rate of the reverse reaction.
- Answer: B) The forward and reverse reactions are occurring at the same rate.
- The reaction rate for which of the following orders of reaction is constant over time?
- A) Zero-order reaction
- B) First-order reaction
- C) Second-order reaction
- D) Third-order reaction
- Answer: A) Zero-order reaction
- For a reaction that is exothermic, how does the equilibrium constant change with increasing temperature?
- A) The equilibrium constant increases
- B) The equilibrium constant decreases
- C) The equilibrium constant remains unchanged
- D) The equilibrium constant becomes zero
- Answer: B) The equilibrium constant decreases
- What happens to the rate of a reaction if the activation energy is increased?
- A) The rate increases
- B) The rate decreases
- C) The rate remains the same
- D) The rate becomes zero
- Answer: B) The rate decreases
- Which of the following conditions will not affect the equilibrium constant of a reaction?
- A) Changing the temperature
- B) Changing the pressure
- C) Changing the concentration of reactants
- D) Adding a catalyst
- Answer: D) Adding a catalyst
- Which of the following is true for a reaction that has reached dynamic equilibrium?
- A) The forward reaction has stopped.
- B) The reverse reaction has stopped.
- C) The rates of the forward and reverse reactions are equal.
- D) The concentrations of reactants and products are equal.
- Answer: C) The rates of the forward and reverse reactions are equal.
- In a reaction with a rate law of rate = k[A][B]^2, what is the overall order of the reaction?
- A) Zero-order
- B) First-order
- C) Second-order
- D) Third-order
- Answer: D) Third-order