Inter chemistry chemical kinetics most VVI objective question || 12th chemistry most VVI objective question Chapter 4

Inter vvi objective question

Classical 12th chemistry Chapter – 4 VVI objective For Bihar Board and all other board In English medium

Chemical Kinetics

1. By which of the following a catalyst increases the rate of reaction ?
(A) Decreasing internal energy
(B) Decreasing activation energy
(C) Increasing activation energy
(D) None of these
Ans – B
2. The temp. coefficient of most of the reaction lies between :
(A) 1 and 3
(B) 2 and 3
(C) 1 and 4
(D) 2 and 4
Ans – B
3. Order of reaction is decided by
(A) Temperature
(B) Mechanism of reaction
(C) Molecularity
(D) Pressure
Ans – B
4. Half-life of a hypothetical reaction is found to be inversely proportional to the cube of initial concentration. The order of reaction is :
(A) 4
(B) 3
(C) 5
(D) 2
Ans – A
5. A catalyst :
(A) Increases the average kinetic energy of reacting molecules
(B) Increases the activation energy
(C) Alters the activation energy
(D) Increases the frequency of collisions of reacting species
Ans – C
6. The temp coefficient of most of the reaction lies between :
(A) 1 and 2
(B) 2 and 3
(C) 1 and 4
(D) 2 and 4
Ans – B
7. Which one of the following statement about the order of a reaction is true ?
(A) the order of a reaction can only be determined by experiments
(B) The order of a reaction increases with increase in the temperature
(C) the order of a reaction can be determined from balanced equation
(D) A second order reaction is also biomolecular
Ans – A

Inter chemistry chemical kinetics most VVI objective

8. The rate of chemical reaction is doubled for every 10 degree Celsius rise in temperature because of :
(A) Increases in the activation energy
(B) Decreases in the activation energy
(C) Increases in the number of molecular collision
(D) Increases in the number of activated molecules
Ans D
9. The half life of radioactive isotope is three hours. If the initial mass of isotope was 300 gm, the mass which remained undecayed after 18 hours would be :
(A) 4.68 gm
(B) 2.34 gm
(C) 1.17 gm
(D) 9.36 gm
Ans – A
10. The specific rate contant of a first order reaction depends on the :
(A) Concentration of reactant
(B) Time
(C) Concentration of product
(D) Temperature
Ans – A
11. the unit of rate constant and rate of reaction are identical for :
(A) Zero-order reaction
(B) First-order reaction
(C) Second-order reaction
(D) Reversible reaction
Ans – A
12. During the course of a chemical reaction, the rate of a reaction :
(A) Remains constant throughout
(B) Increases as the reaction proceeds
(C) Decreases as the reaction proceeds
(D) First increases followed by a decrease
Ans – C
13. The rate constant does not depend upon :
(A) Temperature
(B) Pressure
(C) Activation energy
(D) Catalyst
Ans – B
14. The order of a reaction :
(A) Is never equal to zero or fraction
(B) Is a theoretical parameter and can be predicted from the expression of the over-all chemical equation
(C) Is always equal to the total stoichiometric number of the chemical equation
(D) Is always determined experimentally
Ans – D

Inter chemistry chemical kinetics most VVI objective

15. The activation energy is a chemical reaction is defined as :
(A) The difference in energies of reactants and products
(B) The sum of energies of reactants and products
(C) The difference in energy of intermediate complex with the average energy of reactants and products
(D) The difference in energy of intermediate complex and the average energy of reactants

Ans – C
16. The use of catalyst helps in :
(A) Increasing the rate of forward reaction only
(B) Increasing the rate of backward reaction only
(C) Increasing the rates of both forward and backward reactions
(D) Increasing the relative amount of products
Ans – C
17. The reaction is high molecularity are rare because :
(A) Many body collisions have a low probability
(B) Many body collisions are not favoured energetically
(C) Activation energy of many body collisions is very large
(D) Very high concentration is required for such reactions
Ans – A
18. The half-Life period of any first order reaction :
(A) Is half the specific rate constant
(B) Is always the same irrespective of the reaction
(C) Is independent of initial concentration
(D) In directly proportional to initial concentration of reactants
Ans – C
19. The dimensions of rate constant of 2nd order reaction involves :
(A) Concentration
(B) Concentration and time
(C) Time only
(D) Neither time nor concentration
Ans – B
20. Collision theory is applicable to :
(A) First order reactions
(B) Zero order reactionsi
(C) Biomolecular reactions
(D) Intramolecular reactions
Ans – C

Inter vvi objective question