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 5 of 29
- A. (a) First order
- B. (b) Second order
- C. (d) Zero order
- D. (c) Third order
Explanation: The correct answer for the order of the reaction N2O5 → 2N2O5 + O2 is:(a) First orderHere's why the other options are incorrect:(b) Second…
Correct answer: (a) First order- A. Single
- B. Square
- C. Cube
- D. (d) Raise to power four
Explanation: For a 3rd order reaction, the relationship between the half-life and the initial concentration of reactants is:(b) SquareThe half-life of…
Correct answer: Square- A. (a) First order
- B. (b) Second order
- C. (c) Third order
- D. (d) Zero order
Explanation: The relation t1/2 = 1/Ka correctly points towards a (b) Second order reaction.
Correct answer: (b) Second order- A. (a) Spectrophotometer method
- B. (e) Optical relation method
- C. (b) Dilatometric method
- D. (d) Refractometric method
Explanation: The correct answer to the question "Radiations are absorbed in" is:(a) Spectrophotometer methodHere's why the other options are…
Correct answer: (a) Spectrophotometer method- A. Pressure
- B. (b) Effective collisions
- C. (c) Ineffective collisions
- D. Temperature
Explanation: The correct answer for the formation of an activated complex is:(b) Effective collisionsHere's why the other options are incorrect:(a)…
Correct answer: (b) Effective collisions- A. Endothermic
- B. Exothermic
- C. (c) Moderate reaction
- D. (d) No reaction
Explanation: The correct answer for what happens when the energy of reactants is higher than the energy of products is:(b) Exothermic reactionHere's…
Correct answer: Exothermic- A. molecularity of the reaction
- B. order of the reaction
- C. Specific activity of the reaction
- D. Rate constant of the reaction
Explanation: In a chemical reaction, the order of the reaction refers to the dependence of the reaction rate on the concentration of reactants.
Correct answer: order of the reaction- A. increase with increase in concentration of the reactants
- B. decreases with increase in concentration of the reactants
- C. increases with increase in concentration of the products
- D. decreases with increase in concentration of the products
Explanation: When a compound reacts with sulfuric acid, the reaction rate generally decreases with an increase in the concentration of the reactants.
Correct answer: decreases with increase in concentration of the reactants- A. increase with increase in concentration of the reactants
- B. Decreases with increase in concentration of the reactants
- C. Increases with increase in concentration of the products
- D. Decreases with increase in concentration of the products
Explanation: For an irreversible reaction, the rate of the reaction typically increases with an increase in the concentration of the reactants.
Correct answer: increase with increase in concentration of the reactants- A. A is a molecule of the reactant
- B. A is a molecule of the product
- C. A is proportionality constant
- D. A is Arrhenius constantarhi
Explanation: In the Arrhenius equation, A represents the pre-exponential factor or the Arrhenius constant.
Correct answer: A is Arrhenius constantarhi- A. I is a second order reactioN
- B. II and III are first order reactions
- C. III is a first order reaction.
- D. I and II are first order reactions
Explanation: Let's analyze each reaction:LN₂O₃→ 2NO2 + 0.502This reaction involves the decomposition of dinitrogen pentoxide (N₂O₃) into nitrogen…
Correct answer: I and II are first order reactions- A. Fe2O3 and Al2O3 are catalysts while K₂O is a promoteR
- B. Fe2O3 is catalyst while AO3 and K2O are promoter
- C. Al2O3 and K2O are catalysts while Al2O3 is a promoteR
- D. Fe2O3 and K2O are catalysts while Al2O3 is a promoter
Explanation: In the given reaction for the production of ammonia, N₂ + 3H2 → 2NH3, the catalysts listed are Al2O3, K2O, and Fe2O3.The correct answer…
Correct answer: Fe2O3 is catalyst while AO3 and K2O are promoter- A. 0.5
- B. 4
- C. 2
- D. 1
Explanation: In the balanced chemical equation: 2N2O5 4NO2 + O2.The stoichiometric coefficient of N205 is 2, and the stoichiometric coefficient of NO2…
Correct answer: 1- A. Unimolecular reaction
- B. First-order reaction
- C. Second-order reaction
- D. Bimolecular reaction
Explanation: A unimolecular reaction involves the decomposition of a single molecule into products.
Correct answer: Unimolecular reaction- A. Decrease in activation energy of reaction
- B. Decrease in the number collisions between reactant molecules
- C. Increase in activation energy of reactants
- D. Increase in number of effective collisions
Explanation: A unimolecular reaction involves the decomposition When the temperature of a reaction increases, the kinetic energy of the reactant…
Correct answer: Increase in number of effective collisions- A. 1.1 times that of half-life
- B. 2.2 times that of half-life
- C. 3.3 times that of half life
- D. 4.4 times that of half-life
Explanation: For first-order reactions, the time it takes for the reactant concentration to decrease to 10% of its initial value (90% completion) is…
Correct answer: 3.3 times that of half life- A. Increases as the reaction proceeds
- B. Decreases as the reaction proceeds
- C. May increase or decrease during the reaction
- D. Remains constant as the reaction proceeds
Explanation: The rate of a chemical reaction is the speed at which reactants are converted into products.
Correct answer: May increase or decrease during the reaction- A. Kc = X^2 / (a - x)(b - x)
- B. Kc =X2/(a-x)v
- C. Kc =4X2/(a-x)v
- D. Kc =4X2v2/(a-x)(b-3x)3
Explanation: Kc: This represents the equilibrium constant for the reaction, not the rate expression itself.
Correct answer: Kc = X^2 / (a - x)(b - x)- A. Which resist in change in PH and POH
- B. Only in PH
- C. Only POH
- D. Does not resist
Explanation: Buffer solutions are solutions that resist changes in pH when an acid or base is added to them.
Correct answer: Which resist in change in PH and POH- A. Oxidation no method
- B. Ion electron method
- C. Both
- D. None
Explanation: Redox chemical reactions involve the transfer of electrons between reactants.
Correct answer: Both