NEET Chemistry 2020 - Chemical Kinetics

Question - 1

The correct difference between first and second order reactions is that :

• A A first-order reaction can catalyzed; a second-order reaction cannot be catalyzed.
• B The half-life of a first-order reaction does not depend on [A]0;the half-life of a second-order reaction does depend on [A]0.
• C The rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations.
• D The rate of a first-order reaction does depend on reactant concentrations; the rate of a secondorder reaction does not depend on reactant concentrations.

Question - 2

When initial concentration of the reactant is doubled, the half-life period of a zero-order reaction :

• A Is tripled
• B Is doubled
• C Is halved
• D Remains unchanged

Question - 3

The decomposition of phosphine (PH3) on tungsten at low pressure is a first-order reaction. It is because the :

• A rate is proportional to the surface coverage
• B rate is inversely proportional to the surface coverage
• C rate is independent of the surface coverage
• D rate of decomposition is very slow.

Question - 4

The rate of first-order reaction is 0.04 mol L-1 s-1 at 10 seconds and 0.03 mol L-1 s-1 at 20 seconds after initiation of the reaction. The half-life period of the reaction is :

• A 44.1 s
• B 54.1s
• C 24.1s
• D 34.1s

Question - 5

When initial concentration of a reaction is doubled in a reaction, its half-life period is not affected. The order of the reaction is :

• A zero
• B second
• C first
• D more than zero but less than first

Question - 6

The rate constant of the reaction A $\longrightarrow$ B is 0.6 X 10-3 mole per second. If the concentration of A is 5M then concentration of B after 20 min is :

• A 1.08 M
• B 3.60 M
• C 0.36 M
• D 0.72 M

Question - 7

In a reaction, A + B ⟶ Product, rate is doubled when the concentration of B is doubled and rate increases by a factor of 8 when the concentrations of both the reactants (A and B) are doubled. Rate law for the reaction can be written as :

• A rate = k [A][B]2
• B rate = k [A]2 [B]2
• C rate = k [A][B]
• D rate = k [A]2 [B]

Question - 8

Which one of the following statement for the order of a reaction is incorrect?

• A Order is not influenced by stoichiometric coefficient of the reactants
• B Order of reaction is sum of power to the concentration terms of reactants to express the rate of reaction
• C Order of reaction is always whole number
• D Order can be determined only experimentally

Question - 9

For the reaction,  ${ N }_{ 2 }{ O }_{ 5{ (g) } }\longrightarrow 2N{ O }_{ 2{ (g) } }+\frac { 1 }{ 2 } { O }_{ 2{ (g) } }$ The value of rate of disappearance of N2O5 is given as 6.25 x 10-3 mol L-1s-1. The rate of formation of NO2 and O2 is given respectively as :

• A 6.25 x 10-3 mol L-1 s-1and 6.25 x 10-3 mol L-1 s-1
• B 1.25 x 10-2 mol L-1s-1 and 3.125 x 10-3 mol L-1s-1
• C 6.25 x 10-3 mol L-1s-l and 3.125 x 10-3 mol L-1 s-1
• D 1.25 x 10-2 mol L-1s-1 and 6.25 x 10-3 mol L-1s-1

Question - 10

During the kinetic study of the reaction, 2A + B ⟶ C + D, following results were obtained :

 Run A/mol L-1 B/mol L-1 Initial rate of formation of d/mol L-1min-1 I 0.1 0.1 6.0 x 10-3 II 0.3 0.2 7.2 x 10-2 III 0.3 0.4 2.88 x 10-1 IV 0.4 0.1 2.40 x 10-2

Based on the above data which one of the followmg is correct?

• A Rate = k [A]2[B]
• B Rate = k [A][B]
• C Rate = k [A]2[B]2
• D Rate = k [A][B]2