JEE Chemistry Chemical Kinetics MCQs Set A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

Question. Which of the following reaction does not occur fastly ?
(a) Rusting of iron
(b) Burning of LPG for cooking
(c) Burning of gasoline
(d) None of these

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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) Msec^–1, sec^–1
(c) sec^–1, M
(d) M, sec^–1.

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

Question. The rate law for a reaction between the substances A and B is given by Rate = k [A]ⁿ [B]^m On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be as
(a) 2^{(n – m)}
(b) (m + n)
(c) (n – m)
(d) None of these

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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) 2
(b) zero
(c) 1
(d) 3

Answer: A

Question. The unit of rate constant for a zero order reaction is
(a) mol L^–1 s^–1
(b) L mol^–1 s^–1
(c) s^–1
(d) None of these

Answer: A

Question. The rate constant of a reaction is 3.00 × 10³ L mol^–1 sec^–1. The order of this reaction will be
(a) 2
(b) 0
(c) 1
(d) 3

Answer: A

Question. Which of the following is not a first order reaction ?
(a) Decomposition of HI on gold surface
(b) Natural radioactive decay of unstable nuclei
(c) Hydrogenation of ethene
(d) None of these

Answer: A

Question. The plot of concentration of the reactant vs time for a reaction is a straight line with a negative slope. The reaction follows a rate equation
(a) zero order
(b) second order
(c) first order
(d) third order

Answer: A

Question. The half-life of a reaction is inversely proportional to the square of the initial concentration of the reactant. Then the order of the reaction is
(a) 3
(b) 1
(c) 0
(d) 2

Answer: A

Question. Half life of a first order reaction is 4s and the initial concentration of the reactant is 0.12 M. The concentration of the reactant left after 16 s is
(a) 0.0075 M
(b) 0.03 M
(c) 0.06 M
(d) 0.015 M

Answer: A

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) 23.1 min
(b) 7.53 min
(c) 0.383 min
(d) 8.73 min

Answer: A

Question. The rate constant for a first order reaction whose half-life, is 480 seconds is
(a) 1.44 × 10 ^–3 sec^–1
(b) 2.88 × 10^–3 sec^–1
(c) 2.72 × 10^–3 sec^–1
(d) None of these

Answer: A

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

Answer: A

Question. Point out the wrong statement: For a first order reaction
(a) the unit of k is mole^–1 min^–1
(b) time for half-change × rate constant = 0.693
(c) change in the concentration unit does not change the rate constant (k)
(d) time for half-change (t_1/2) is independent of initial concentration

Answer: A

Question. The value of rate constant of a pseudo first order reaction _________.
(a) depends on the concentration of reactants present in small amount
(b) depends on the concentration of reactants present in excess.
(c) is independent on the concentration of reactants
(d) depends only on temperature

Answer: A

Question. In the Haber process for the manufacture of ammonia the following catalyst is used
(a) Iron with molybdenum as promoter
(b) Platinized asbestos
(c) Copper oxide
(d) Alumina

Answer: A

Question. What is the activation energy for a reaction if its rate doubles when the temperature is raised from 20°C to 35°C? (R = 8.314 J mol^–1 K^–1)
(a) 34.7 kJ mol^–1
(b) 342 kJ mol^–1
(c) 269 kJ mol^–1
(d) None of these

Answer: A

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) 512
(b) 614
(c) 112
(d) 400

Answer: A

Question. If the activation energy for the forward reaction is 150 kJ mol^–1 and that of the reverse reaction is 260 kJ mol^–1, what is the enthalpy change for the reaction ?
(a) –110 kJ mol^–1
(b) – 410 kJ mol^–1
(c) 410 kJ mol^–1
(d) 110 kJ mol^–1

Answer: A

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

Answer: A