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 19 of 29
- A. 4
- B. 1.5
- C. 2.5
- D. Zero
Explanation: The formation of carbon tetrachloride from chloroform is shown below : CHCl3+CL2→CCl4+HCl Rate=k[CHCl3 ][Cl ]1/2 The sum of exponents will…
Correct answer: 1.5- A. 2NO2 + CO --> 2NO + CO2
- B. NO2 + NO2 --> NO3+NO
- C. NO2+NO --> NO + CO2
- D. NO2+CO --> NO + CO2
Explanation: The proposed mechanism for this reaction is as follows.Slow :NO2(g) + NO2(g)→NO3(g) + NO(g) (rate determining step)Fast :NO3 (g) +…
Correct answer: NO2 + NO2 --> NO3+NO- A. Change in concentration
- B. Change in volume
- C. Change in pressure
- D. Change in temperature
Explanation: Dilatometric method is useful for those reactions, which involve small volume changes in solutions.The volume change is directly…
Correct answer: Change in volume- A. Lowering the activation energy
- B. Increasing the activation energy
- C. Lowering the frequency or effective collisions between reactive molecules
- D. Increasing the frequency or effective collision between reactive molecules
Explanation: This option is correct. Increasing the temperature provides more kinetic energy to the molecules, leading to higher collision frequency…
Correct answer: Increasing the frequency or effective collision between reactive molecules- A. Potential energy
- B. Activation energy
- C. Kinetic energy
- D. Ionization energy
Explanation: The minimum amount of energy, required for an efective collision(start the reaction) is called activation energy.
Correct answer: Activation energy366. As the number of effective collisions between the reacting particles increases, the rate of reaction
- A. Decreases
- B. Increases
- C. Remains the same
- D. Both B and C
Explanation: Rate of reaction depends upon number of effective collisions between reactant molecules. As collisions increase, the rate also increases.
Correct answer: Increases- A. 2
- B. 1/2
- C. 4
- D. 1/4
Explanation: In a second-order reaction, the rate of reaction is proportional to the square of the concentration of the reactant(s).
Correct answer: 4- A. A first order reaction
- B. Independent or the initial concentration or the salt
- C. A second order reaction
- D. A zero order reaction
Explanation: The given reaction, Diazonium salt (C6H5N2Cl) decomposing into C6H5Cl (chlorobenzene) and N2 (nitrogen gas), follows the equation…
Correct answer: A first order reaction- A. Decrease in temperature and concentration of reactants
- B. Decrease in temperature and increase in concentration of reactants
- C. Increase in temperature and decrease in concentration of reactants
- D. Increase in temperature and increase in concentration of reactants
Explanation: Option d is correct. Both increasing temperature and concentration of reactants lead to an increase in the rate of reaction.
Correct answer: Increase in temperature and increase in concentration of reactants- A. Second order reaction
- B. Pseudo first order reaction
- C. Zero order reaction
- D. First order reaction
Explanation: When one reactant is taken in excess compared to the other in a chemical reaction, the reaction effectively becomes pseudo-first order…
Correct answer: Pseudo first order reaction- A. 1,1
- B. 1,2
- C. 2,0
- D. 2,1
Explanation: The molecularity of a reaction refers to the number of molecules or atoms that are involved as reactants in a single elementary reaction…
Correct answer: 2,1372. The molecularity of reaction: CH3COOC2H5 + H2O ⇌ CH3COOH + C2H5OH is 2. The order of reaction is:
- A. 0
- B. 1
- C. 2
- D. Pseudo first order reaction.
Explanation: The rate of reaction remains efectively independent of the concentration of water because,being a solvent, it is present in very large…
Correct answer: Pseudo first order reaction.- A. First order
- B. Second order
- C. Third order
- D. Fractional order
Explanation: Explanation for this question will be added soon.
Correct answer: Second order- A. I
- B. II
- C. III
- D. II and III
Explanation: Order of a reaction is an experimentally determined value. It is zero for reaction III.
Correct answer: III375. Which aluminum sample would react most rapidly with 1 M CuSO4 solution under the same conditions?
- A. 1 g Al rod
- B. 1 g Al pellets
- C. 1 g Al ribbon
- D. 1 g Al powder
Explanation: Option D, 1 g of Al powder, would react most rapidly with 1 M CuSO4 solution under the same conditions.
Correct answer: 1 g Al powder- A. Molecularity of reaction
- B. Concentration terms
- C. Order of reaction
- D. Number of reactants
Explanation: The order of reaction indicates how the rate of a reaction depends on the concentration of reactants.
Correct answer: Order of reaction- A. mol dm-1 s-1
- B. mol-1 dm3 s-1
- C. s-1
- D. mol-2 dm6 s-1
Explanation: Option D is correct because it provides the correct units for a second-order reaction with respect to A and a first-order reaction with…
Correct answer: mol-2 dm6 s-1- A. Rapid decrease in concentration of reactants
- B. Rapid increase in the concentration of products
- C. Fast rate of reaction
- D. All of the above
Explanation: Option d is correct because it encompasses all of the effects observed when the slope of the graph is steepest at the beginning of a…
Correct answer: All of the above- A. First order
- B. Third order
- C. Second order
- D. Zero order
Explanation: In a zero-order reaction, the rate of the reaction is constant and does not depend on the concentration of the reactant.
Correct answer: Zero order- A. Order of reaction
- B. Rate of reaction
- C. Half-life period of reaction
- D. Rate determining step
Explanation: Option A is correct because studying the order of reaction can guide us towards understanding the mechanism of the reaction by revealing…
Correct answer: Order of reaction