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 4 of 29
- A. Rate=k
- B. Rate = k[A][B]
- C. Rate = k[A]
- D. Rate = k[B]
Explanation: Rate laws or rate equations are mathematical expressions that describe the relationship between the rate of a chemical reaction and the…
Correct answer: Rate = k[A]- A. T½ = k/0.693
- B. T½ = 0.693/k
- C. None of these
- D. T½ = 0.693k
Explanation: The half-life of first-order reactions is given by the equation:T1/2 = 0.693/kwhere 'k' is the rate constant.
Correct answer: T½ = 0.693/k- A. Overall order of reaction
- B. Order of reaction with respect to A
- C. All of these
- D. Order of reaction with respect to B
Explanation: The overall order of the reaction is determined by adding the individual orders which in the given equation are given by 'a' and 'b' where…
Correct answer: Overall order of reaction- A. ax b
- B. a - b
- C. b - a
- D. a + b
Explanation: In any chemical reaction, we can have more than two reactants reacting and giving some products.
Correct answer: a + b- A. Negative order reaction
- B. First order reaction
- C. Zero order reaction
- D. Second order reaction
Explanation: In second-order reactions, the rate of reaction is directly proportional to the square of the concentration of the concerned reactant.
Correct answer: Second order reaction- A. 1
- B. 2
- C. 3
- D. 4
- E. 5
Explanation: The order of a reaction is determined by summing the exponents of the concentration terms in the rate law.
Correct answer: 3- A. conc.s-1
- B. M2s-1
- C. s-1
- D. M-1s-1
- E. M-1s-2
Explanation: The unit of the rate constant for a first-order reaction is s-1. This is because, for a first-order reaction, the rate is directly…
Correct answer: s-1- A. First order reaction
- B. Zero order reaction
- C. Second order reaction
- D. Third order reaction
Explanation: Rate law general form:Rate = k[A]n n = order of reactionk = rate constantUnit of k depends on the order:k = Rate[A]n
Correct answer: Zero order reaction- A. Instantaneous rate
- B. Constant rate
- C. Average rate
- D. All of these
Explanation: The rate of reaction between two specific intervals is called the average rate of reaction because it is calculated by taking the change…
Correct answer: Average rate- A. 6 x 10^-3mol dm-3 sec-1
- B. 6 x 10^-4 mol dm-3 sec-1
- C. 6 x 10^-2 mol dm-3 sec-1
- D. 6 x 10^-5 mol dm-3 sec-1
Explanation: 𝑟𝑎𝑡𝑒 𝑜𝑓 𝑟𝑒𝑎𝑐𝑡𝑖𝑜𝑛 = Δ𝐶/𝑡 = (6 × 10−4 )/10 = 6 × 10−5𝑚𝑜𝑙𝑑𝑚−3𝑠𝑒𝑐−1 Given: Change in concentration = 6 x 10^(-4) mol…
Correct answer: 6 x 10^-5 mol dm-3 sec-1- A. Rate = k [NO] [O2]
- B. Rate = k [NO]2[O2]
- C. Rate = k [NO2]2
- D. Rate = k [NO2]
Explanation: The rate equation involves reactants, not products. Assuming the coefficients in the reaction equation represent the orders of reaction…
Correct answer: Rate = k [NO]2[O2]- A. rate constant
- B. reaction speed
- C. rate of a reaction
- D. All of these
Explanation: The rate of a reaction can be represented as the rate of change of concentrations of either the products or the reactants.
Correct answer: rate of a reaction- A. In fraction
- B. Negative
- C. Positive
- D. All of these
Explanation: Rate of reaction = amount of product form/timeA positive sign indicates reaction proceeding in the forward direction, a negative sign…
Correct answer: All of these- A. (a) Rate of formation of N2O5
- B. (b) Rate of decomposition of N2O5
- C. (c) Order of the reaction
- D. (d) None.
Explanation: The correct answer is:(b) Rate of decomposition of N2O5Here's why the other options are incorrect:(a) Rate of formation of N2O5: The sign…
Correct answer: (b) Rate of decomposition of N2O5- A. Temperature
- B. (b) Effective collision
- C. (c) Concentration of reactants
- D. (d) Chemical nature of reactants and products
Explanation: and rearrangements of atoms involved.(b) Effective collision: Effective collisions provide the minimum energy required for a reaction to…
Correct answer: (d) Chemical nature of reactants and products- A. Slow
- B. Moderate
- C. (d) not natural
- D. (c) Fast
Explanation: The correct answer for the nature of spontaneous reactions is:(c) FastHere's why the other options are incorrect:(a) Moderate: While some…
Correct answer: (c) Fast- A. (a) Concentration of reactant does not change
- B. (b) Concentration of product increases
- C. (c) Concentration of reactant decreases
- D. (d) Concentration of reactant increases
Explanation: The correct answer is:(c) Concentration of reactant decreasesHere's why the other options are incorrect:(a) Concentration of reactant does…
Correct answer: (c) Concentration of reactant decreases- A. (a) I and II quadrant
- B. (b) II and III quadrant
- C. C)III and IV quadrant
- D. (d) II and IV quadrant
Explanation: The correct answer for the location of the straight line on the graph between 1/T on the x-axis and log k on the y-axis is:(a) I and II…
Correct answer: (a) I and II quadrant- A. (a) Rate of reaction
- B. (b) Rate of formation of product
- C. (c) Energy released during reaction
- D. (d) a and b
Explanation: The correct answer for what the rate of disappearance of a reactant is equal to is:(d) Both a and b (Rate of reaction and Rate of…
Correct answer: (d) a and b- A. (a) Arrhenius constant
- B. Molecularity
- C. (c) Specific rate constant
- D. (d) Ideal rate constant
Explanation: The correct answer for the rate of reaction when the concentrations of reactants are taken as unity is:(c) Specific rate constantHere's…
Correct answer: (c) Specific rate constant