Please refer to Chapter 4 Chemical Kinetics MCQ Class 12 Chemistry with answers below. These multiple-choice questions have been prepared based on the latest NCERT book for Class 12 Chemistry. Students should refer to MCQ Questions for Class 12 Chemistry with Answers to score more marks in Grade 12 Chemistry exams. Students should read the chapter Chemical Kinetics and then attempt the following objective questions.

MCQ Questions Class 12 Chemistry Chapter 4 Chemical Kinetics

The Chemical Kinetics MCQ Class 12 Chemistry provided below covers all important topics given in this chapter. These MCQs will help you to properly prepare for exams.

Question. Which of the following reaction does not occur fastly ?
(a) Precipitation of AgCl by mixing aqueous solutions of AgNO₃ and NaCl.
(b) Burning of gasoline
(c) Rusting of iron
(d) Burning of LPG for cooking

Question. The unit of rate of reaction is
(a) mole/dm³
(b) mole/pound
(c) mole/dm³ sec
(d) mole/cm³

Question. The term – dc/dt in a rate equation refers to :
(a) the conc. of a reactant
(b) the decrease in conc. of the reactant with time
(c) the velocity constant of reaction
(d) None of these

Question. Rate of which reaction increases with temperature :
(a) of any type of reactions
(b) of exothemic reactions
(c) of endothemic reactions
(d) of none

Question. Chemical kinetics is a study to find out
(a) the feasibility of a chemical reaction
(b) extent to which a reaction will proceed
(c) speed of a reaction
(d) All of the above

Question. In the rate equation, when the conc. of reactants is unity then rate is equal to
(a) specific rate constant
(b) average rate constant
(c) instantaneous rate constant
(d) None of above

Question. Rate of a reaction can be defined as
(a) the rate of decrease in concentration of any one of the reactants
(b) the rate of increase in concentration of any one of the products
(c) the rate of decrease in concentration of any one of the reactants or the rate of increase in concentration of any one of the products
(d) the sum of rate of decrease in concentration of all the reactants or the rate of increase in concentration of all the products

Question. The rate of reaction
(a) increases as the reaction proceeds
(b) decreases as the reaction proceeds
(c) remains the same as the reaction proceeds
(d) may decrease or increase as the reaction proceeds

Question. The rate of reaction between two specific time intervals is called
(a) instantaneous rate
(b) average rate
(c) specific rate
(d) ordinary rate

Question. In a slow reaction, rate of reaction generally ………. with time:
(a) decreases
(b) increases
(c) sometimes increases and sometimes decreases.
(d) remains constant

Question. Instantaneous rate of a chemical reaction is
(a) rate of reaction in the beginning
(b) rate of reaction at the end
(c) rate of reaction at a given instant
(d) rate of reaction between two specific time intervals

Question. At the beginning the decrease in the conc. of reactants is
(a) slow
(b) moderate
(c) rapid
(d) None of above

Question. The rate of a chemical reaction tells us about,
(a) the reactants taking part in reaction
(b) the products formed in the reaction
(c) how slow or fast the reaction is taking place
(d) None of the above

Question. The average rate and instantaneous rate of a reaction are equal
(a) at the start
(b) at the end
(c) in the middle
(d) when two rate have time interval equal to zero

Question. Which one of the following statements for the order of a reaction is incorrect ?
(a) Order can be determined only experimentally.
(b) Order is not influenced by stoichiometric coefficient of the reactants.
(c) Order of reaction is sum of power to the concentration terms of reactants to express the rate of reaction.
(d) Order of reaction is always whole number.

Question. Order of reaction can be
(a) 0
(b) fraction
(c) whole number
(d) integer, fraction, zero

Question. The rate of reaction depends upon the
(a) volume
(b) force
(c) pressure
(d) conc. of reactants

Question. Units of rate constant of first and zero order reactions in terms of molarity M unit are respectively
(a) sec^–1, Msec^–1
(b) sec^–1, M
(c) Msec^–1, sec^–1
(d) M, sec^–1.

Question. Order of reaction is decided by
(a) temperature
(b) mechanism of reaction as well as relative concentration of reactants
(c) molecularity
(d) pressure

Question. Velocity constant k of a reaction is affected by
(a) change in the concentration of the reactant
(b) change of temperature
(c) change in the concentration of the product
(d) None of the above

Question. A zero order reaction is one whose rate is independent of
(a) the concentration of the reactants
(b) the temperature of reaction
(c) the concentration of the product
(d) the material of the vessel in which reaction is carried out

Question. In the reaction 2A + B→A₂B, if the concentration of A is doubled and that of B is halved, then the rate of the reaction will:
(a) increase 2 times
(b) increase 4 times
(c) decrease 2 times
(d) remain the same

Question. A reaction involving two different reactants can never be
(a) bimolecular reaction
(b) second order reaction
(c) first order reaction
(d) unimolecular reaction

Question. 3A→ B+ C, it would be a zero order reaction when
(a) the rate of reaction is proportional to square of concentration of A
(b) the rate of reaction remains same at any concentration of A
(c) the rate remains unchanged at any concentration of B and C
(d) the rate of reaction doubles if concentration of B is increased to double

Question. If the rate of the reaction is equal to the rate constant, the order of the reaction is
(a) 3
(b) 0
(c) 1
(d) 2

Question. Which one of the following reactions is a true first order reaction?
(a) Alkaline hydrolysis of ethyl acetate
(b) Acid catalyst hydrolysis of ethyl acetate
(c) Decomposition of N₂O
(d) Decomposition of gaseous ammonia on a hot platinum surface

Question. In a reaction, when the concentration of reactant is increased two times, the increase in rate of reaction was four times. Order of reaction is :
(a) zero
(b) 1
(c) 2
(d) 3

Question. The order of a reaction, with respect to one of the reacting component Y, is zero. It implies that:
(a) the reaction is going on at a constant rate
(b) the rate of reaction does not vary with temperature
(c) the reaction rate is independent of the concentration of Y
(d) the rate of formation of the activated complex is zero

Question. Which of the following is not a first order reaction ?
(a) Hydrogenation of ethene
(b) Natural radioactive decay of unstable nuclei
(c) Decomposition of HI on gold surface
(d) Decomposition of N₂O

Question. The rate of a first order reaction is 1.5 × 10^–2 mol L^–1 min^–1 at 0.5 M concentration of the reactant. The half life of the reaction is
(a) 0.383 min
(b) 23.1 min
(c) 8.73 min
(d) 7.53 min

Question. A reaction proceeds by first order, 75% of this reaction was completed in 32 min. The time required for 50% completion is
(a) 8 min
(b) 16 min
(c) 20 min
(d) 24 min

Question. If the rate of a gaseous reaction is independent of pressure, the order of reaction is:
(a) 0
(b) 1
(c) 2
(d) 3

Question. In an exothermic reaction if ΔH is the enthalpy then activation energy is
(a) more than ΔH
(b) less than ΔH
(c) equal to ΔH
(d) none of the above

Question. The minimum energy required for the reacting molecules to undergo reaction is :
(a) potential energy
(b) kinetic energy
(c) thermal energy
(d) activation energy

Question. In terms of the ‘Collision Theory of Chemical Kinetics’, the rate of a chemical reaction is proportional to
(a) the change in free energy per second
(b) the change in temperature per second
(c) the number of collisions per second
(d) the number of products molecules

Question.The rate of reaction is doubled for every 10°C rise in temperature. The increase in reaction rate as a result of temperature rise from 10°C to 100°C is
(a) 112
(b) 512
(c) 400
(d) 614

Question. Activation energy of a chemical reaction can be determined by
(a) evaluating rate constant at standard temperature
(b) evaluating velocities of reaction at two different temperatures
(c) evaluating rate constants at two different temperatures
(d) changing concentration of reactants

Question. The reason for almost doubling the rate of reaction on increasing the temperature of the reaction system by 10°C is
(a) the value of threshold energy increases
(b) collision frequency increases
(c) the fraction of the molecule having energy equal to threshold energy or more increases
(d) activation energy decreases

Question. According to collision theory, which of the following is NOT a true statement concerning a catalyst?
(a) A catalyst changes the temperature of reaction.
(b) The mechanism of a reaction will change when a catalyst is added.
(c) A catalyst provides a different activation energy for a reaction.
(d) A catalyst changes the speed of a reaction, but not the equilibrium constant.

Question. Which of the following has been used to explain the subject of chemical kinetics
(a) Collision theory of bimolecular reactions
(b) The activated complex theory
(c) Arrhenius equation
(d) All of these

Question. In a reaction, the threshold energy is equal to
(a) activation energy + normal energy of reactants
(b) activation energy – normal energy of reactants
(c) normal energy of reactants – activation energy
(d) average kinetic energy of molecules of reactants

Question. Which of the following influences the rate of a chemical reaction performed in solution?
(a) Temperature
(b) Activation energy
(c) Presence of a catalyst
(d) All of the above influence the rate

Question. Collision theory is applicable to
(a) first order reactions
(b) zero order reactions
(c) bimolecular reactions
(d) intra-molecular reactions

Question. Which one of the following is wrongly matched ? 
(a) Saponification of CH₃COOC₂H₅ — second order reaction
(b) Hydrolysis ofCH₃COOCH₃ — pseudo unimolecular reaction
(c) Decomposition of H₂O₂ — first order reaction
(d) Combination of H₂ and Br₂ to give HBr — first order reaction

Question. The unit of rate constant of second order reaction
(a) t^-1
(b) conc^-1 t^-1
(c) conet^-1
(d) conc^-2 t^-1

Question. If ‘a’ and ‘t_1/2 ‘ are initial concentration of reactant and half-life of a zero order reaction respectively, which of the following is correct ? 
(a) t_1/2 ∝ 1/a
(b) t_1/2 ∝ a
(c) t_1/2 ∝ 1/a²
(d) t_1/2 ∝ a2

Question. The rate constant of a reaction is found to be 3 x 10^-3 mol L^-1 min^-1. The order of the reaction is
(a) zero
(b) 1
(c) 2
(d) 1.5

Question. The decomposition of N₂O₅ occurs as
2N₂O₅ — 4NO₂ + O₂ , and follows Ist order kinetics, hence 
(a) the reaction is unimolecular
(b) the reaction is bimolecular
(c) t_1/2 ∝ a⁰
(d) None of the above

Question. Rate of a reaction can be expressed by following rate expression Rate = k[ A]²[ B], if concentration of A is reduced by half by what times concentration of B is to be increased to have same rate of reaction ?
(a) 4 times
(b) 2 times
(c) 1/4 times
(d) 8 times

Question. The rate constant ofa first order reaction is 6.9 x 10^-3 s^-1 How much time will it take to reduce the initial concentration to its 1/ 8th value ? 
(a) 100s
(b) 200s
(c) 300 s
(d) 400 s

Question. Which one of the following statement for order of reaction is not correct ?
(a) Order can be determined experimentally
(b) Order of reaction is equal to sum of the power of concentration terms in differential rate law
(c) It is not affected with stoichiometric coefficient of the reactants
(d) Order cannot be fractional

Question. t_1/4can be taken as the time taken for the concentration of a reactant to drop to 3 / 4 of its initial value. If the rate constant for a first order reaction is k, the t_1/4 can be written as
(a) 0.75/ k
(b) 0.69/ k
(c) 0.29/ k
(d) 0.10/ k

Question. A reaction involving two different reactants can never be
(a) bimolecular reaction 
(b) second order reaction
(c) first order reaction
(d) uni molecular reaction

Question. In the first order reaction, the concentration of the reactants is reduced to 25% in one hour. The half-life period of the reaction is
(a) 2 h
(c) 1/2 h
(b) 4 h
(d) 1/4 h

Question. For a reaction, X (g) → Y (g) + Z(g)
the half-life period is 10 min. In what period of time would the concentration of X be reduced to 10% of original concentration ? 
(a) 20 min
(b) 33 min
(c) 15 min
(d) 25 min

Question. The rate law for the chemical reaction
2NO₂Cl → 2NO₂ + Cl₂ is
rate = k [NO₂ ][Cl] . The rate determining step is
(a) 2NO₂CI → 2NO₂ + 2CI 
(b) NO₂ + Cl2 → NO₂Cl + Cl
(c) NO₂Cl +Cl → NO₂ + Cl₂
(d) NO₂CI → NO₂+ Cl

Question. For the reaction A + B ➔ C, it is found that doubling the concentration of A increases the rate by four times and doubling the concentration of B doubles the reaction rate. What is the overall order of the reaction ? 
(a) 4
(b) 3/2
(c) 3
(d) 1

Question. A first order reaction is 10% complete in 20 min. The time taken for 19% completion is 
(a) 30 min
(b) 40 min
(c) 50 min
(d) 38 min
(e) 45 min

Question. A catalyst increases rate of reaction by
(a) decreasing enthalpy
(b) decreasing internal energy
(c) decreasing activation energy
(d) increasing activation energy

Question. According to the collision theory of reaction rates, the rate of reaction increases with temperature due to
(a) greater number of collision
(b) higher velocity of reacting molecules
(c) greater number of molecules having the activation energy
(d) decrease in the activation energy

Question. According to which theory activation energy and proper orientation of the molecules together determine the criteria for an effective collision ?
(a) Arrhenius theory
(b) Activated complex theory
(c) Collision theory
(d) Both (a) and (c)

Question. Activation energy of the reaction is
(a) the energy released during the reaction
(b) the energy evolved when activated complex is formed
(c) minimum amount of energy needed to overcome the potential barrier
(d) the energy needed to form one mole of the product

Question. In most cases, for a rise of 10K temperature the rate constant is doubled to tribled. This is due to the reason that
(a) collision frequency increases by a factor of 2 to 3.
(b) fraction of molecules possessing threshold energy increases by a factor of 2 to 3
(c) Activation energy is lowered by a factor of 2 to 3.
(d) none of these

Question. The integrated rate equations can be determined for
(a) zero order reactions
(b) first order reactions
(c) second order reactions
(d) Both (a) and (b)

Question. Activation energy of a chemical reaction can be determined by ___________
(a) determining the rate constant at standard temperature.
(b) determining the rate constants at two temperatures.
(c) determining probability of collision.
(d) using catalyst.

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