Preparing for the Joint Entrance Exam (JEE) can be a daunting task. With so many subjects to cover and so many topics to study, it can be challenging to know where to start. One essential topic in the JEE Mains syllabus is the Chemical Kinetics. In this article, we will provide 50+ MCQ questions on the Chemical Kinetics, along with detailed solutions to help you prepare for the JEE Mains exam.
These 50+ MCQ questions are selected by the experts of studyrate.in and these are more difficult questions, which will help you to better understand Chemical Kinetics JEE Mains MCQ Questions with Answers.
Chemical Kinetics JEE Mains MCQ
Which of the following factors does not affect the rate of a chemical reaction? a) Temperature b) Concentration of reactants c) Surface area of reactants d) Volume of the reaction vessel
Answer: d) Volume of the reaction vessel
Explanation: The volume of the reaction vessel does not directly affect the rate of a chemical reaction. Factors such as temperature, concentration of reactants, and surface area of reactants can influence the rate of a reaction.
The rate of a chemical reaction can be determined by: a) The change in concentration of reactants over time b) The change in volume of reactants over time c) The change in pressure of reactants over time d) The change in temperature of reactants over time
Answer: a) The change in concentration of reactants over time
Explanation: The rate of a chemical reaction is often determined by monitoring the change in concentration of reactants over time. It provides a quantitative measure of how quickly the reactants are being converted into products.
Which of the following is not a method to determine the order of a reaction? a) Initial rate method b) Integrated rate method c) Half-life method d) Equilibrium constant method
Answer: d) Equilibrium constant method
Explanation: The equilibrium constant method is used to determine the extent of a reaction at equilibrium, not the order of a reaction. The order of a reaction is determined using the initial rate method, integrated rate method, or half-life method.
The rate constant (k) of a first-order reaction has the unit of: a) M/s b) M-1s-1 c) s/M d) s-1
Answer: d) s-1
Explanation: The rate constant (k) of a first-order reaction has the unit of reciprocal time, i.e., s-1. It represents the fraction of reactants that react per unit time.
The half-life of a first-order reaction is independent of: a) The initial concentration of the reactant b) The rate constant of the reaction c) The temperature of the reaction d) The order of the reaction
Answer: a) The initial concentration of the reactant
Explanation: The half-life of a first-order reaction is independent of the initial concentration of the reactant. It depends only on the rate constant and the order of the reaction.
Which of the following statements about the rate constant (k) is correct? a) The rate constant increases with increasing temperature. b) The rate constant decreases with increasing concentration of reactants. c) The rate constant is independent of the nature of the reactants. d) The rate constant is a constant value for all reactions.
Answer: a) The rate constant increases with increasing temperature.
Explanation: The rate constant (k) generally increases with increasing temperature. This is in accordance with the Arrhenius equation, which describes the temperature dependence of the rate constant.
The activation energy (Ea) of a chemical reaction can be determined from the: a) Rate constant (k) at a specific temperature b) Initial concentration of reactants c) Change in enthalpy (∆H) of the reaction d) Equilibrium constant (K) of the reaction
Answer: a) Rate constant (k) at a specific temperature
Explanation: The activation energy (Ea) of a chemical reaction can be determined from the rate constant (k) at a specific temperature using the Arrhenius equation: k = Ae^(-Ea/RT), where R is the gas constant, T is the temperature, and A is the pre-exponential factor.
Which of the following factors does not affect the rate constant of a reaction? a) Temperature b) Pressure c) Catalyst d) Nature of the reactants
Answer: b) Pressure
Explanation: Pressure does not directly affect the rate constant of a reaction. Factors such as temperature, catalyst, and nature of the reactants can influence the rate constant.
The rate of a reaction doubles when the concentration of the reactant is doubled. The order of the reaction with respect to that reactant is: a) Zero order b) First order c) Second order d) Third order
Answer: b) First order
Explanation: If the rate of a reaction doubles when the concentration of a reactant is doubled, it indicates a first-order reaction with respect to that reactant.
The rate-determining step of a reaction is: a) The fastest step of the reaction mechanism b) The slowest step of the reaction mechanism c) The first step of the reaction mechanism d) The last step of the reaction mechanism
Answer: b) The slowest step of the reaction mechanism
Explanation: The rate-determining step of a reaction, also known as the slowest step, is the step with the highest activation energy. It determines the overall rate of the reaction.
The rate law for a reaction is given by the expression rate = k[A]^2[B]^3. What is the overall order of the reaction? a) 2 b) 3 c) 5 d) 6
Answer: c) 5
Explanation: The overall order of a reaction is the sum of the individual orders with respect to each reactant. In this case, the overall order is 2 + 3 = 5.
For a reaction to occur, the reactant molecules must possess: a) Sufficient kinetic energy b) Proper orientation c) Both kinetic energy and proper orientation d) Neither kinetic energy nor proper orientation
Answer: c) Both kinetic energy and proper orientation
Explanation: For a reaction to occur, the reactant molecules must possess both sufficient kinetic energy to overcome the activation energy barrier and proper orientation for effective collisions.
The rate of a reaction can be increased by: a) Decreasing the temperature b) Increasing the concentration of reactants c) Adding an inhibitor d) Increasing the volume of the reaction vessel
Answer: b) Increasing the concentration of reactants
Explanation: Increasing the concentration of reactants increases the frequency of collisions, leading to more effective collisions and an increased rate of reaction.
Which of the following statements about a catalyst is correct? a) A catalyst increases the activation energy of a reaction. b) A catalyst is consumed in the reaction. c) A catalyst appears in the balanced chemical equation. d) A catalyst alters the equilibrium constant of a reaction.
Answer: c) A catalyst appears in the balanced chemical equation.
Explanation: A catalyst participates in the reaction but is not consumed itself. It appears in the balanced chemical equation but is not included in the stoichiometric coefficients.
The rate of a reaction can be determined experimentally by measuring the change in: a) Volume of the reactants b) Pressure of the reactants c) Temperature of the reactants d) Concentration of the reactants
Answer: d) Concentration of the reactants
Explanation: The rate of a reaction is often determined by measuring the change in concentration of the reactants over time. This provides a quantitative measure of the rate of reaction.
The order of a reaction can be determined from the: a) Balanced chemical equation of the reaction b) Rate law expression for the reaction c) Activation energy of the reaction d) Equilibrium constant of the reaction
Answer: b) Rate law expression for the reaction
Explanation: The order of a reaction can be determined from the rate law expression, which relates the rate of reaction to the concentrations of the reactants. The exponents in the rate law expression represent the order with respect to each reactant.
The half-life of a second-order reaction depends on: a) The initial concentration of the reactant b) The rate constant of the reaction c) The temperature of the reaction d) The order of the reaction
Answer: a) The initial concentration of the reactant
Explanation: The half-life of a second-order reaction is inversely proportional to the initial concentration of the reactant. It depends on the rate constant and the order of the reaction as well.
The rate constant (k) of a reaction increases with: a) Decreasing temperature b) Increasing pressure c) Increasing activation energy d) Increasing temperature
Answer: d) Increasing temperature
Explanation: The rate constant (k) of a reaction generally increases with increasing temperature. This is in accordance with the Arrhenius equation, which shows the exponential relationship between the rate constant and temperature.
The Arrhenius equation is given by k = Ae^(-Ea/RT). Which of the following represents the activation energy (Ea) in the equation? a) k b) A c) R d) T
Answer: a) k
Explanation: In the Arrhenius equation, the activation energy (Ea) is represented by the term in the exponent, (-Ea/RT), where R is the gas constant, T is the temperature, and k is the rate constant.
The rate constant (k) of a zero-order reaction has the unit of: a) M/s b) M-1s-1 c) s/M d) s-1
Answer: a) M/s
Explanation: The rate constant (k) of a zero-order reaction has the unit of concentration per unit time, which is M/s.
The rate law for a reaction is rate = k[A]^2[B]. If the concentration of reactant A is doubled while keeping the concentration of reactant B constant, how does the rate of the reaction change? a) It doubles b) It quadruples c) It remains unchanged d) It decreases by half
Answer: b) It quadruples
Explanation: According to the given rate law, the rate is proportional to the square of the concentration of reactant A. Therefore, if the concentration of A is doubled, the rate will increase by a factor of 2^2 = 4.
The rate constant (k) of a reaction depends on: a) Temperature only b) Concentration of reactants only c) Activation energy only d) Temperature and activation energy
Answer: d) Temperature and activation energy
Explanation: The rate constant (k) of a reaction depends on both temperature and activation energy. Temperature affects the rate of reaction by influencing the kinetic energy of molecules, while activation energy determines the barrier that molecules must overcome to react.
The half-life of a first-order reaction is independent of: a) The initial concentration of the reactant b) The rate constant of the reaction c) The temperature of the reaction d) The order of the reaction
Answer: a) The initial concentration of the reactant
Explanation: The half-life of a first-order reaction is independent of the initial concentration of the reactant. It depends only on the rate constant and the order of the reaction.
The rate law for a reaction is rate = k[A]^[B]. What is the order of the reaction? a) Zero order with respect to A, first order with respect to B b) First order with respect to A, zero order with respect to B c) First order with respect to A, first order with respect to B d) Zero order with respect to A, zero order with respect to B
Answer: c) First order with respect to A, first order with respect to B
Explanation: The order of a reaction is determined by the exponents in the rate law expression. In this case, the order is 1 with respect to both A and B.
Which of the following factors does not affect the rate of a reaction? a) Catalyst b) Surface area of solid reactants c) Pressure of gaseous reactants d) Volume of the reaction vessel
Answer: d) Volume of the reaction vessel
Explanation: The volume of the reaction vessel does not directly affect the rate of a reaction. Factors such as catalyst, surface area of solid reactants, and pressure of gaseous reactants can influence the rate.
The rate law for a reaction is rate = k[A]^[B]. If the concentration of reactant A is tripled while keeping the concentration of reactant B constant, how does the rate of the reaction change? a) It triples b) It increases by a factor of 9 c) It remains unchanged d) It decreases by a factor of 3
Answer: a) It triples
Explanation: According to the given rate law, the rate is directly proportional to the concentration of reactant A. Therefore, if the concentration of A is tripled, the rate will also triple.
Which of the following statements about the rate constant (k) is correct? a) The rate constant increases with increasing temperature. b) The rate constant decreases with increasing concentration of reactants. c) The rate constant is independent of the nature of the reactants. d) The rate constant is a constant value for all reactions.
Answer: a) The rate constant increases with increasing temperature.
Explanation: The rate constant (k) generally increases with increasing temperature. This is in accordance with the Arrhenius equation, which describes the temperature dependence of the rate constant.
The reaction A → B follows first-order kinetics. If the concentration of A is reduced to one-fourth of its initial value, how does the time taken for the reaction to be 75% complete change? a) It remains unchanged b) It is halved c) It is doubled d) It is quadrupled
Answer: b) It is halved
Explanation: In a first-order reaction, the time taken for the reaction to be a certain percentage complete is constant. Therefore, if the concentration of A is reduced to one-fourth, the time taken for 75% completion will be halved.
The rate-determining step of a reaction is: a) The fastest step of the reaction mechanism b) The slowest step of the reaction mechanism c) The first step of the reaction mechanism d) The last step of the reaction mechanism
Answer: b) The slowest step of the reaction mechanism
Explanation: The rate-determining step of a reaction, also known as the slowest step, is the step with the highest activation energy. It determines the overall rate of the reaction.
The rate of a reaction is found to be proportional to the square of the concentration of a reactant. What is the order of the reaction with respect to that reactant? a) Zero order b) First order c) Second order d) Third order
Answer: c) Second order
Explanation: The rate being proportional to the square of the concentration indicates a second-order reaction with respect to that reactant.
We hope there JEE MCQ of Class 12 : Chemical Kinetics will help you to score an excellent rank in JEE Mains and Advanced. If you have any queries feel free to write in the comments section. We at Study Rate are always ready to serve our students.
