JEE Chemistry Chemical Kinetics MCQs Set B

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

Answer: A

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

Answer: A

Question. The activation energy for a reaction is 9.0 kcal/mol. The increase in the rate constant when its temperature isincreased from 298K to 308K is
(a) 63%
(b) 50%
(c) 10%
(d) 100%

Answer: A

Question. In a reversible reaction the energy of activation of the forward reaction is 50 kcal. The energy of activation for the reverse reaction will be
(a) either greater than or less than 50 kcal
(b) 50 kcal
(c) > 50 kcal
(d) < 50 kcal

Answer: B

Question. Which of the following statements best describes how a catalyst works?
(a) A catalyst lowers the activation energy for the reaction by providing a different reaction mechanism
(b) A catalyst destroys some of the reactants, which lowers the concentration of the reactants.
(c) A catalyst decreases the temperature of the reaction which leads to a faster rate
(d) A catalyst changes the potential energies of the reactants and products

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

Question. In Arrhenius plot, intercept is equal to
(a) ln A
(b) log10a
(c) ln k
(d) None of these

Answer: A

Question. A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be k1 and k2 respectively. then
(a) k2 = 0.25 k1
(b) k1 = 4k1
(c) k2 = 2k1
(d) None of these

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A

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

Answer: A