MCAT General Chemistry Freestanding Practice Questions: Kinetics

Home > MCAT Test > MCAT general chemistry practice tests

Test Information

Question 7 questions

Time minutes

See All test questions

Take more free MCAT general chemistry practice tests available from maintests.com.

1. In the reaction A + 2 B → C, the rate law is experimentally determined to be rate = k[B]2. What happens to the initial rate of reaction when the concentration of A is doubled?

  • A. The rate doubles.
  • B. The rate quadruples.
  • C. The rate is halved.
  • D. The rate is unchanged.

2. Which of the following statements is always true about the kinetics of a chemical reaction?

  • A. The rate law includes all reactants in the balanced overall equation.
  • B. The overall order equals the sum of the reactant coefficients in the overall reaction.
  • C. The overall order equals the sum of the reactant coefficients in the slow step of the reaction.
  • D. The structure of the catalyst remains unchanged throughout the reaction progress.

3. Which of the following is represented by a localized minimum in a reaction coordinate diagram?

  • A. Transition state
  • B. Product
  • C. Activated complex
  • D. Intermediate

4. Which factor always affects both thermodynamic and kinetic properties?

  • A. Temperature
  • B. Transition state energy level
  • C. Reactant coefficients of the overall reaction
  • D. No single factor always affects both thermodynamics and kinetics.

5. Which of the following best describes the role of pepsin in the process of proteolysis?

  • A. It stabilizes the structure of the amino acid end products.
  • B. It lowers the energy requirement needed for the reaction to proceed.
  • C. It increases the Keq of proteolysis.
  • D. It lowers the free energy of the peptide reactant.

6. Based on the reaction mechanism shown below, which of the following statements is correct?

2 NO + O2 → 2 NO2

1) 2 NO → N2O2 (fast)

2) N2O2 + O2 → 2 NO2 (slow)

  • A. Step 1 is the rate-determining step and the rate of the overall reaction is k[N2O2].
  • B. Step 1 is the rate-determining step and the rate of the overall reaction is k[NO]2.
  • C. Step 2 is the rate-determining step and the rate of the overall reaction is k[NO2]2.
  • D. Step 2 is the rate-determining step and the rate of the overall reaction is k[N2O2][O2].

7. When table sugar is exposed to air it undergoes the following reaction:

C12H22O11 + 12 O2 → 12 CO2 + 11 H2O

(∆G = -5693 kJ/mol)

When this reaction is observed at the macroscopic level, it appears as though nothing is happening, yet one can detect trace amounts of CO2 and H2O being formed. These observations are best explained by the fact that the reaction is:

  • A. thermodynamically favorable but not kinetically favorable.
  • B. kinetically favorable but not thermodynamically favorable.
  • C. neither kinetically nor thermodynamically favorable.
  • D. both kinetically and thermodynamically favorable.