Class 12 Chemistry Chapter 4 Chemical Kinetics MCQs | Class 12 Chemistry Chapter 4 Chemical Kinetics Multiple Choice Questions (MCQs) and Answers

Advertisement
Questions
1 Which of the following observations is incorrect about the order of a reaction?
A Order of a reaction is always a whole number
B The stoichiometric coefficient of the reactants doesn’t affect the order
C Order of reaction is the sum of power to express the rate of reaction to the concentration terms of the reactants
D Order can only be assessed experimentally

Answer:Order of a reaction is always a whole number
2 The rate constant of  zero-order reactions has the unit
A s-1
B mol L-1 s-1
C L2 mol-2 s-1
D L mol-1 s-1

Answer:mol L-1 s-1
3 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

Answer: increase 2 times
4 When the rate of the reaction is equal to the rate constant, the order of the reaction is
A zero order
B first order
C second order
D third order

Answer: zero order
5 A substance ‘A’ decomposes by a first-order reaction starting initially with [A] = 2.00M and after 200min, [A] becomes 0.15M. For this reaction t1/2 is
A 53.72 min
B 50.49 min
C 48.45 min
D 46.45 min

Answer: 53.72 min
6 In the Haber process for the manufacture of ammonia the following catalyst is used
A Platinized asbestos
B Iron with molybdenum as a promoter
C Copper oxide
D Alumina

Answer:Iron with molybdenum as a promoter
7 The activation energy in 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

Answer:the difference in energy of intermediate complex and the average energy of reactants
8 Rate of which reaction increases with temperature?
A Exothermic reaction
B Endothermic reaction
C (a) and (b) both
D None of the above

Answer:(a) and (b) both
9 A plot of log (a – x) against time t is a straight line. This indicates that the reaction is of
A zero order
B first order
C second order
D third order

Answer:first order
10 Radioactive disintegration is an example of
A zero order reaction
B first order reaction
C second order reaction
D third order reaction

Answer:first order reaction
11 A first order reaction has a rate constant 1.15 × 10-3s-1. How long time will 5 g of this reactant take to reduce to 3 g?
A 444 s
B 400 s
C 528 s
D 669 s

Answer:444 s
12 A first order reaction takes 40 min for 30% decomposition. What will be t12?
A 77.7 min
B 52.5 min
C 46.2 min
D 22.7 min

Answer: 77.7 min
13 In pseudo unimolecular reactions
A both the reactants are present in low concentration
B both the reactants are present in same concentration
C one of the reactant is present in excess
D one of the reactant is non-reactive

Answer: one of the reactant is present in excess
14 Half life period of a first order reaction is 10 min. What percentage of the reaction will be completed in 100 min?
A 25%
B 50%
C 99.9%
D 75%

Answer:99.9%
15 Rate constant in case of first order reaction is
A inversely proportional to the concentration units
B independent of concentration units
C directly proportional to concentration units
D inversely proportional to the square of concentration units

Answer:independent of concentration units
16 The order of reaction is decided by
A temperature
B mechanism of reaction as well as relative concentration of reactants
C molecularity
D pressure

Answer: mechanism of reaction as well as relative concentration of reactants
17 The overall rate of a reaction is governed by
A the rate of fastest intermediate’step
B the sum total of the rates of all intermediate steps
C the average of the rates of all the intermediate steps
D the rate of slowest intermediate step

Answer: the rate of slowest intermediate step
18 Fora unimolecular reaction
A the order and molecuiarity of the slowest step are equal to one
B molecuiarity of the reaction can be zero, one or two
C molecuiarity of the reaction can be determined only experimentally
D more than one reacting species are involved in one step

Answer:the order and molecuiarity of the slowest step are equal to one
19 The number of molecules of the reactants taking part in a single step of the reaction is indicative of
A order of a reaction
B molecuiarity of a reaction
C fast step of the mechanism of a reaction
D half-life of the reaction

Answer: molecuiarity of a reaction
20 The unit of rate and rate constant are same fora
A zero order reaction
B first order reaction
C second order reaction
D third order reaction

Answer: zero order reaction

ADRE 2.0 FULL LENGTH MOCK TEST

Take Mock Tests

Missiles Mock Test Start Test!
SSC MTS Mock Test Start Test
IBPS CLERK MOCK TEST Start Test
SSC MTS 2022 JULY 26 Shift 1 (ENGLISH) Start Test!
SSC GD Previous Year Paper 2021 Nov 17 Shift - I (Hindi) Start Test!
SSC CGL Tier - 1 PYP 2022 April 21 Shift- 1 (ENGLISH) Start Test!
MPSC PAPER I MOCK TEST 1 (ENGLISH) Start Test!
IB Security Assistant Mock test 1 (english) Start Test!
UP POLICE CONSTABLE MOCK TEST 1 Start Test!
DELHI POLICE CONSTABLE MOCK TEST 1 (HINDI) Start Test!

Chapters

Advertisement
Assam Direct Recruitment Test Series