Free Reaction Kinetics MCQs with Answers
573 Reaction Kinetics MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.
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573 questions · page 14 of 29
- A. 1
- B. 2
- C. 3
- D. 4
Explanation: The overall order of a rate equation is determined by adding up the individual orders of all the reactants involved.
Correct answer: 3- A. Heterogeneous catalyst
- B. Homogeneous catalyst
- C. Slow
- D. Fast
Explanation: In homogeneous catalysis, the catalyst and the reactants are in the same phase, typically a liquid or gas.
Correct answer: Homogeneous catalyst- A. 1
- B. 2
- C. 0
- D. 3
Explanation: The formula for finding the order of the reaction isK=(dm3mol-1)^1-n s-1.
Correct answer: 2- A. 1s-1
- B. 0.3 s-1
- C. 0.6 s-1
- D. 0.9 s-1
Explanation: The constant which defines the relationship between the molar concentration of the reactants and the rate of the chemical reaction is…
Correct answer: 0.6 s-1- A. First order
- B. Second onder
- C. Fractional order
- D. Third order
Explanation: The decomposition of n2o5 is a first-order reaction.
Correct answer: First order- A. It is high energy species
- B. It is a stable species
- C. It is an unstable specie
- D. Potential energy is maximum at activated complex stage
Explanation: The activated complex is temporary and unstable because the energy is more elevated than the products or reactants.
Correct answer: It is a stable species- A. Doubled
- B. halved
- C. One fourth
- D. quadrupled
Explanation: When a reaction is said to be first order with respect to a reactant, it means that the rate of the reaction is directly proportional to…
Correct answer: Doubled- A. Increasing the frequency of collisions
- B. Increasing the proportion of particles with energy greater than the activation
- C. Increasing the activation energy
- D. Increasing the concentration
Explanation: A catalyst primarily functions by increasing the proportion of particles with energy greater than the activation energy required for the…
Correct answer: Increasing the proportion of particles with energy greater than the activation- A. Arrhenius constant
- B. Ideal rate constant
- C. Molecularity
- D. Specific rate constant
Explanation: Specific rate constant, is the rate constant that relates the concentrations of reactants to the rate of reaction when the reactants'…
Correct answer: Specific rate constant- A. Number of moles per dm2
- B. Number of moles per dm3
- C. Gram per dm'
- D. Number of moles
- E. Number of molecules
Explanation: The term "active mass" in the Law of Mass Action refers to the concentration of a substance involved in a chemical reaction, usually…
Correct answer: Number of moles per dm3- A. Change in concentration of substance/Time taken for the change
- B. Time taken for the change+ Change in concentration of substance
- C. Time taken for the change+ Change in concentration of substance x 100
- D. Time taken for the change x Change in concentration of substance
Explanation: The rate measures how fast a reaction occurs, which means we need to determine how much the concentration of a reactant or product changes…
Correct answer: Change in concentration of substance/Time taken for the change- A. Rate=k[A](B)
- B. Rate= k[A]^a[B]^b,
- C. Rate=k[A]a
- D. Rate=k[B]b
Explanation: Option B is correct.Reaction orders (a and b) are determined experimentally and do not necessarily match the stoichiometric coefficients a…
Correct answer: Rate= k[A]^a[B]^b,- A. 3rd order
- B. 2nd order
- C. Ist order
- D. Zero order
Explanation: The rate of a zero-order reaction is constant and does not depend on the concentration of the reactants.
Correct answer: Zero order- A. K-Ae^-Ea/QT
- B. K=Ae^-Ea/RT
- C. K=Ae^-Ea/ST
- D. K=Ae^-Ea/UT
Explanation: Option B is the correct Arrhenius equation, where A is the pre-exponential factor, Ea is the activation energy, R is the gas constant, and…
Correct answer: K=Ae^-Ea/RT- A. decrease in volume on product side
- B. increase in volume on product side
- C. increase in volume on reactant side
- D. simultaneous increase and decrease of product
Explanation: This implies more moles of gases on the product side than on the reactant side, making Δn positive. Hence, Kp>Kc
Correct answer: increase in volume on product side- A. (mol-dm3)-151
- B. mol(dm3)s1
- C. mol(dm3)-1s
- D. mol(dm3)-1s-1
Explanation: The unit of rate of reaction is molarity per unit time i.e mol/dm3/s.
Correct answer: mol(dm3)-1s-1- A. K=9 x 10^-35
- B. K = 12 x 10^-35
- C. K= 6 x 10^-125
- D. K = 15 x 10^-125
Explanation: D is the correct option.We wanted to let u know this is actual szambu paper 2024 question this question was impossible to solve because…
Correct answer: K = 15 x 10^-125- A. 30 min
- B. 60 min
- C. 90 min
- D. 120 min
Explanation: Fraction remaining=(1/2)nwhere n is the number of half lives.If 87.5% of the reaction is complete, this means 12.5% of the reactant…
Correct answer: 90 min279. A reaction is first order with respect to A and second order with respect to B, the rate equation is
- A. rate = k [A] [B]2
- B. rate = k [A]2[B]
- C. rate = k [A] [B]
- D. rate = k [A]
Explanation: The correct rate equation is rate = k [A] [B]2. This equation correctly reflects that the reaction is first order with respect to A and…
Correct answer: rate = k [A] [B]2- A. 0.012 mol dm-3 s-1
- B. 0.014 mol dm-3 s-1
- C. 0.016 mol dm-3 s-1
- D. 0.018 mol dm-3 s-1
Explanation: For a first-order reaction, the rate of the reaction can be calculated using the following formula:Rate=k×[A]Rate=0.0458s−1 ×0.35mol…
Correct answer: 0.016 mol dm-3 s-1