Unit 8: Chemical Reactivity
- What effect does increasing the surface area of a solid reactant have on the reaction rate?
- A) It decreases the rate of reaction
- B) It has no effect on the rate of reaction
- C) It increases the rate of reaction
- D) It changes the equilibrium constant
- Answer: C) It increases the rate of reaction
- Which of the following best describes a chemical equilibrium?
- A) The forward and reverse reactions are not occurring
- B) The rate of the forward reaction is greater than the reverse reaction
- 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
- What does the term “rate-determining step” refer to?
- A) The fastest step in a reaction mechanism
- B) The slowest step in a reaction mechanism
- C) The step that produces the most products
- D) The step that uses the most reactants
- Answer: B) The slowest step in a reaction mechanism
- In a reaction where the concentration of reactants is increased, the equilibrium position will shift:
- A) To the right if the reaction is exothermic
- B) To the left if the reaction is endothermic
- C) To the right if the reaction is endothermic
- D) It will not shift
- Answer: C) To the right if the reaction is endothermic
- Which of the following is true for a reaction that has reached equilibrium?
- A) The concentrations of reactants and products are equal.
- B) The rates of the forward and reverse reactions are equal.
- C) The reaction has stopped completely.
- D) The reaction proceeds only in the forward direction.
- Answer: B) The rates of the forward and reverse reactions are equal.
- The effect of a catalyst on a reaction can be described as:
- A) Increasing the activation energy
- B) Changing the equilibrium constant
- C) Lowering the activation energy
- D) Altering the reaction mechanism
- Answer: C) Lowering the activation energy
- Which of the following factors does not affect the equilibrium constant?
- A) Temperature
- B) Pressure
- C) Concentration of reactants and products
- D) Presence of a catalyst
- Answer: D) Presence of a catalyst
- For a reaction with a rate constant of 0.01 s^-1, what is the order of the reaction?
- A) Zero-order
- B) First-order
- C) Second-order
- D) Third-order
- Answer: B) First-order
- Which of the following changes will increase the rate of a reaction between two gases?
- A) Decreasing the pressure
- B) Increasing the temperature
- C) Decreasing the temperature
- D) Adding an inert gas
- Answer: B) Increasing the temperature
- Which of the following represents a chemical reaction that is in dynamic equilibrium?
- A) The concentrations of reactants and products are changing rapidly.
- B) The concentrations of reactants and products remain constant over time.
- C) The reaction has stopped completely.
- D) The reaction proceeds only in one direction.
- Answer: B) The concentrations of reactants and products remain constant over time.