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 8 of 29
- A. Rate = k[A][B]
- B. Rate = k[A]2[B]
- C. Rate = k[A][B]2
- D. Rate = k[A]2[B]2
Explanation: Rate is directly proportional to concentration of A and concentration of B so it is 2 order reaction. Rate = K [A][B].
Correct answer: Rate = k[A][B]- A. Refractometric method
- B. Dilatometric method
- C. Optical rotation method
- D. Spectrometric method
Explanation: Refractometry is a method for measuring a substance's refractive index to assess its composition or purity.
Correct answer: Refractometric method- A. 5g
- B. 10g
- C. 15g
- D. 20g
Explanation: No. of half life periods = Total time/Time of one half life period = 10/2.5 = 4 Now we know that the quantity left after 'n' half-life…
Correct answer: 10g- A. Fractional order reaction
- B. Pseudo 1st order reaction
- C. 1st order reaction
- D. 2nd order reaction
Explanation: Although the reaction is second order overall (first order in ethyl acetate and first order in H₂O), water is in large excess, so its…
Correct answer: Pseudo 1st order reaction- A. 1
- B. 2
- C. 3
- D. 0
Explanation: The order of a reaction indicates how the rate depends on reactant concentration.If doubling the concentration increases the rate…
Correct answer: 2- A. 4
- B. 9
- C. 8
- D. 2
Explanation: The rate law of a reaction is given by:rate = k[A]2 [B].If we double the concentration of both A and B, the new rate of reaction will…
Correct answer: 8- A. By increasing temperature
- B. Using a suitable catalyst
- C. By an increase in activation energy
- D. By increasing conc. Of reactants
Explanation: Activation energy is inversely proportional to the rate of the reaction.
Correct answer: By an increase in activation energy- A. Decreases yield of a reaction
- B. Decreases rate of a reaction
- C. Increase yield of product
- D. Increase rate of a reaction
Explanation: A catalyst is a substance that speeds up a chemical reaction, but is not consumed by the reaction; hence a catalyst can be recovered…
Correct answer: Increase rate of a reaction- A. Zero order
- B. Half order
- C. Second order
- D. First order
Explanation: In First order reactions, the graph represents the half-life is different from zero order reaction in a way that the slope continually…
Correct answer: First order- A. Rate of reaction
- B. Order of reaction
- C. Type of reaction
- D. Product of reaction
Explanation: The order of reaction can be defined as the power dependence of the rate on the concentration of all reactants.
Correct answer: Order of reaction- A. P is a catalyst in this reaction
- B. No P molecules possess sufficient energy to react
- C. The concentration of P does not change during the reaction
- D. The rate of reaction is independent of the concentration of P
- E. The rate of reaction is proportional to the concentration of Q
Explanation: If the order of reaction with respect to P is 0 (zero), this means that the concentration of P doesn't affect the rate of reaction.
Correct answer: The rate of reaction is independent of the concentration of P- A. 16/1
- B. 1/16
- C. 4/1
- D. 1/8
- E. 8/1
Explanation: If the volume of the vessel is reduced by 1/4th that means according to formula C=n/V concentration of each gas in the flask increases by…
Correct answer: 16/1- A. Mole (dm3) sec
- B. Mole (dm3) sec-1
- C. Mole(dm-3) sec -1
- D. Mole(dm3)sec-2
- E. Mole (dm3)-1 sec -2
Explanation: Reaction rates are usually expressed as the concentration of reactant consumed or the concentration of product formed per unit time.
Correct answer: Mole(dm-3) sec -1- A. First order
- B. Pseudo first order
- C. Second order
- D. Third order
- E. Pseudo order
Explanation: The order of the reaction is the sum of all the exponents of reactants in the rate equation.
Correct answer: First order155. The chemical reaction in which reactions require high amount of activation energy are generally:
- A. Slow
- B. First fast then slow
- C. First slow then fast
- D. Spontaneous
Explanation: The activation energy of a chemical reaction is closely related to its rate.
Correct answer: Slow- A. Law of conservation of energy
- B. Law of mass action
- C. Law of conservation of mass
- D. Active mass law
Explanation: The law of mass action states the rate of chemical reaction is directly proportional to the product of the reactant concentration values.
Correct answer: Law of mass action157. A catalyst:
- A. Increases the rate of forward reaction
- B. Increases the rate of both forward and reverse reaction
- C. Changes equilibrium position
- D. Increases the rate of reverse reaction
Explanation: A catalyst increases the rate of both forward and reverse reaction, making the system reach equilibrium faster.
Correct answer: Increases the rate of both forward and reverse reaction- A. Zero order reaction
- B. First order reaction
- C. Second order reaction
- D. Third order reaction
Explanation: For a zero-order reaction, the rate equation is:Rate = K [A]0Where K is the rate constant and A is the reactantSince [A]0 is equal to…
Correct answer: Zero order reaction- A. Thermodynamics
- B. Stoichiometry
- C. Electrochemistry
- D. Chemical Kinetics
Explanation: Chemical kinetics: The branch of physical chemistry that is concerned with understanding how fast or how slow a chemical reaction occurs…
Correct answer: Chemical Kinetics- A. Initial concentration
- B. Temperature
- C. Catalyst
- D. All of above
Explanation: 1st order reactionHalf life time - t1/2 = 0.693/kK = rate constantK is dependent on temperature So, t1/2 is also dependent on temperature.
Correct answer: Temperature