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 25 of 29
- A. The temperature of the reaction
- B. The concentration of reactants
- C. The concentration of products
- D. The presence of a catalyst
Explanation: In a zero-order reaction, the rate of reaction is independent of the concentration of reactants.
Correct answer: The concentration of reactants- A. Initial Conc of Products
- B. Initial Conc of Reactants
- C. Ions
- D. Radicals
Explanation: Zero-order reactions are unique because their reaction rate remains constant and does not depend on the concentration of reactants.
Correct answer: Initial Conc of Reactants- A. Negative
- B. Zero
- C. Equal
- D. Positive
Explanation: When considering reaction kinetics, the average rate of reaction over a given time interval is calculated as the change in concentration…
Correct answer: Equal- A. Area under the curve
- B. Calculating the length of the curve
- C. Drawing a tangent to the curve
- D. All of these options are correct
Explanation: The area under the graph does not give the slope. Calculating the length of the curve does not give the slope.
Correct answer: Drawing a tangent to the curve- A. Ultraviolet radiation
- B. Visible radiation
- C. Infrared radiation
- D. All of these
Explanation: Spectrometry is a versatile analytical method that measures the absorption of electromagnetic radiation by reactants and products.
Correct answer: All of these- A. s-1
- B. mol dm-3 s-1
- C. mol dm-3
- D. mol-1 dm3
Explanation: In a first-order reaction, the rate constant k is derived from the formula: k = rate / [A], where [A] is the concentration of a reactant.
Correct answer: s-1- A. Concentration of the reactants becomes irrelevant
- B. Number of efficient or fruit collisions increase
- C. Reaction proceeds without any transition state
- D. Molecules of the reactants move slowly
Explanation: Rate of reaction is directly proportional to no. of effective collision and inversely proportional to activation energy.
Correct answer: Number of efficient or fruit collisions increase- A. Free energy charge
- B. Wander Waal's equation
- C. Arrhenius equation
- D. Kinetic equation
Explanation: Influence of temperature is predicted by Arrhenius equation reactants Rate =temperature Rate = 1 / Ea
Correct answer: Arrhenius equation- A. Increase rate of a reaction
- B. Decrease rate of reaction
- C. Decrease yield of a reactant
- D. Increase yield of product
Explanation: A positive catalyst increase rate of reaction, decreases activation energy, decrease equilibrium time and changes mechanism of reaction.
Correct answer: Increase rate of a reaction- A. The vessel shall be open
- B. Reacting molecules should have less energy than Ea at time of collision
- C. Reacting molecules must be properly oriented and energy more than or equal to Ea
- D. The reacting molecules must not collide with each other
Explanation: The amount of energy required for effective collisions is called activation energy which is required for effective collision along with…
Correct answer: Reacting molecules must be properly oriented and energy more than or equal to Ea- A. Reactant's concentration
- B. Product concentration
- C. Slowest step
- D. All of these
Explanation: The rate of a chemical reaction is primarily dependent on the concentrations of the reactants.
Correct answer: Reactant's concentration- A. No units
- B. Unit of mol dm-3
- C. Unit as mol dm-3
- D. Unit as mol dm-3s-1
Explanation: The correct answer is D) Unit as mol dm-3 s-1, as it represents the units commonly used to express the rate of reaction.
Correct answer: Unit as mol dm-3s-1- A. Time constant
- B. Relative rate constant
- C. Instantaneous rate constant
- D. Velocity constant
Explanation: The relative rate constant is used when comparing the rates of different reactions, and it can vary from one reaction to another.
Correct answer: Relative rate constant- A. Rising curve
- B. Falling curve
- C. Straight line
- D. None of these
Explanation: During the hydrolysis of an ester, ester bonds are broken down into their respective carboxylic acid and alcohol components.
Correct answer: Rising curve495. A reaction is first order with respect to A and second order with respect to B, the rate equation is
- A. rate = [A] [B]2
- B. rate = k [A]2[B]
- C. rate = k [A] [B]
- D. rate = k [A]
Explanation: In this option the rate of the reaction is proportional to the product of the concentrations of A and B raised to the power of 2.
Correct answer: rate = [A] [B]2496. A catalyst:
- A. Decreases the activation energy and the rate of reaction
- B. Decreases the activation energy and increases the rate of reaction
- C. Increases the activation energy and decreases the rate of reaction
- D. Increases the activation energy and increases the rate of reaction
Explanation: A catalyst is a substance that lowers the activation energy required for a reaction to occur.
Correct answer: Decreases the activation energy and increases the rate of reaction- A. Concentration
- B. Temperature
- C. Catalyst
- D. Activation energy
Explanation: Option d is correct because activation energy does not directly influence the rate of reaction.
Correct answer: Activation energy498. If the reaction 'P +Q → R+ S' is described as being of zero order with respect to P, it means that:
- A. P is catalyst in this reaction
- B. P molecules do not 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
Explanation: Option d is correct because if a reaction is described as being of zero order with respect to a particular reactant (in this case, P), it…
Correct answer: The rate of reaction is independent of the concentration of P- A. mol dm-3 sec-1
- B. mol-2 dm6
- C. sec-1
- D. mole-1 dm3 sec-1
Explanation: Unit of rate = mol dm-3 sec-1 Unit of a second order reaction is = mol2 dm-6 as the rate eqn:- rate = k[reactants]2 ∴ unit of k = unit of…
Correct answer: mole-1 dm3 sec-1- A. Excludes the average kinetic energy of the reactant
- B. Is in addition to the total K.E. of the reactants
- C. Is in addition to the average K.E. of the products
- D. Is needed for effective collisions
Explanation: Activation energy is needed for effective collision.(BOOK INFORMATION)
Correct answer: Is needed for effective collisions