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JEE Advanced > Chemical Kinetics

Explore popular questions from Chemical Kinetics for JEE Advanced. This collection covers Chemical Kinetics previous year JEE Advanced questions hand picked by experienced teachers.

Q 1.

Correct4

Incorrect-1

If uranium (mass number 238 and atomic number 92 ) emits an {tex} \alpha {/tex} -particle, the product has mass no. and atomic no.

A

236 and 92

234 and 90

C

238 and 90

D

236 and 90

Explanation

Q 2.

Correct4

Incorrect-1

The radiations from a naturally occurring radioactive substance, as seen after deflection by a magnetic field in one direction, are:

A

definitely alpha rays

B

definitely beta rays

C

both alpha and beta rays

either alpha or beta rays

Explanation

Q 3.

Correct4

Incorrect-1

The rate constant, the activation energy and the Arrhenius parameter of a chemical reaction at {tex} 25 ^ { \circ } \mathrm { C } {/tex} are {tex} 3.0 \times 10 ^ { - 4 }\ \mathrm { s } ^ { - 1 } , {/tex} {tex} 104.4\ \mathrm { kJ }\ \mathrm { mol } ^ { - 1 } {/tex} and {tex} 6.0 \times 10 ^ { 14 }\ \mathrm { s } ^ { - 1 } {/tex} respectively. The value of the rate constant as {tex} \mathrm { T } \rightarrow \infty {/tex} is,

A

{tex} 2.0 \times 10 ^ { 18 } \mathrm { s } ^ { - 1 } {/tex}

{tex} 6.0 \times 10 ^ { 14 } \mathrm { s } ^ { - 1 } {/tex}

C

infinity

D

{tex} 3.6 \times 10 ^ { 30 } \mathrm { s } ^ { - 1 } {/tex}

Explanation

Q 4.

Correct4

Incorrect-1

{tex} ^ { 27 }_{ 13 } \mathrm { Al } {/tex} is a stable isotope, {tex} ^{29}_{13} \mathrm { Al } {/tex} is expected to disintegrate {tex} \mathrm { by } {/tex}

A

{tex} \alpha {/tex} -emission

{tex} \beta {/tex} -emission

C

positron emission

D

proton emission

Explanation

Q 5.

Correct4

Incorrect-1

The number of neutrons accompanying the formation of {tex}^{139}_{54} \mathrm {Xe} {/tex} and {tex}^{94}_{38} \mathrm {Sr} {/tex} from the absorption of a slow neutron by {tex}^{235}_{92} \mathrm {U} {/tex} , followed by nuclear fission is,

A

0

B

2

C

1

3

Explanation

Q 6.

Correct4

Incorrect-1

The rate constant for the reaction, {tex} 2 \mathrm { N } _ { 2 } \mathrm { O } _ { 5 } \rightarrow 4 \mathrm { NO } _ { 2 } + \mathrm { O } _ { 2 } , {/tex} is {tex} 3.0 \times 10 ^ { - 5 } \mathrm { sec } ^ { - 1 } . {/tex} If the rate is {tex} 2.40 \times 10 ^ { - 5 } \mathrm { mol } {/tex} {tex}\mathrm {litre} ^ { - 1 } \mathrm { sec } ^ { - 1 } , {/tex} then the concentration of {tex} \mathrm { N } _ { 2 } \mathrm { O } _ { 5 } \ \mathrm {(in \ mol \ litre^{-1})} {/tex}is

A

1.4

B

1.2

C

0.04

0.8

Explanation

Q 7.

Correct4

Incorrect-1

If {tex} { 'I' } {/tex} is the intensity of absorbed light and {tex} 'C' {/tex} is the concentration of {tex} A B {/tex} for the photochemical process, {tex} A B \ + \ h v \longrightarrow A B ^ { * } , {/tex} the rate of formation of {tex} A B ^ { * } {/tex} is directly proportional to

A

{tex} \mathrm C {/tex}

{tex} \mathrm I {/tex}

C

{tex} \mathrm I^ { 2 } {/tex}

D

{tex} \mathrm { C }. \mathrm { I } {/tex}

Explanation

Q 8.

Correct4

Incorrect-1

Consider the chemical reaction, {tex} \mathrm { N } _ { 2 } ( \mathrm { g } ) + 3 \mathrm { H } _ { 2 } ( \mathrm { g } ) \rightarrow 2 \mathrm { NH } _ { 3 } ( \mathrm { g } ) {/tex}. The rate of this reaction can be expressed in terms of time derivative of concentration of {tex} \mathrm { N } _ { 2 } ( \mathrm { g } ) , \mathrm { H } _ { 2 } ( \mathrm { g } ) {/tex} or {tex} \mathrm { NH } _ { 3 } ( \mathrm { g } ) {/tex}. Identify the correct relationship amongst the rate expressions.

Rate {tex} = - \mathrm { d } \left[ \mathrm { N } _ { 2 } \right] / \mathrm { dt } = - 1 / 3 \mathrm { d } \left[ \mathrm { H } _ { 2 } \right] / \mathrm { dt } = 1 / 2 \mathrm { d } \left[ \mathrm { NH } _ { 3 } \right] / \mathrm { dt } {/tex}

B

Rate {tex} = - \mathrm { d } \left[ \mathrm { N } _ { 2 } \right] / \mathrm { dt } = - 3 \mathrm { d } \left[ \mathrm { H } _ { 2 } \right] / \mathrm { dt } = 2 \mathrm { d } \left[ \mathrm { NH } _ { 3 } \right] / \mathrm { dt } {/tex}

C

Rate {tex} = \mathrm { d } \left[ \mathrm { N } _ { 2 } \right] / \mathrm { dt } = 1 / 3 \mathrm { d } \left[ \mathrm { H } _ { 2 } \right] / \mathrm { dt } = 1 / 2 \mathrm { d } \left[ \mathrm { NH } _ { 3 } \right] / \mathrm { dt } {/tex}

D

Rate {tex} = - \mathrm { d } \left[ \mathrm { N } _ { 2 } \right] / \mathrm { dt } = - \mathrm { d } \left[ \mathrm { H } _ { 2 } \right] / \mathrm { dt } = \mathrm { d } \left[ \mathrm { NH } _ { 3 } \right] / \mathrm { dt } {/tex}

Explanation


Q 9.

Correct4

Incorrect-1

In a first order reaction the concentration of reactant decreases from {tex} 800\ \mathrm { mol } / \mathrm { dm } ^ { 3 } {/tex} to {tex} 50\ \mathrm { mol } / \mathrm { dm } ^ { 3 } {/tex} in {tex} 2 \times 10 ^ { 4 } \mathrm { sec } . {/tex} The rate constant of reaction in {tex} \mathrm { sec } ^ { - 1 }\ \mathrm { is: } {/tex}

A

{tex} 2 \times 10 ^ { 4 } {/tex}

B

{tex} 3.45 \times 10 ^ { - 5 } {/tex}

{tex} 1.386 \times 10 ^ { - 4 } {/tex}

D

{tex} 2 \times 10 ^ { - 4 } {/tex}

Explanation

Q 10.

Correct4

Incorrect-1

The reaction, {tex} A \rightarrow {/tex} Product, follows first order kinetics. In {tex}40{/tex} minutes the concentration of {tex}A{/tex} changes from {tex}0.1{/tex} to {tex} 0.025\ \mathrm { M } {/tex}. The rate of reaction, when concentration of {tex}A{/tex} is {tex} 0.01\ \mathrm { M } {/tex} is

A

{tex} 1.73 \times 10 ^ { - 4 }\ \mathrm { M }\ \mathrm { min } ^ { - 1 } {/tex}

B

{tex} 3.47 \times 10 ^ { - 5 }\ \mathrm { M }\ \mathrm { min } ^ { - 1 } {/tex}

{tex} 3.47 \times 10 ^ { - 4 }\ \mathrm { M }\ \mathrm { min } ^ { - 1 } {/tex}

D

{tex} 1.73 \times 10 ^ { - 5 }\ \mathrm { M }\ \mathrm { min } ^ { - 1 } {/tex}

Explanation

Q 11.

Correct4

Incorrect-1

Which one of the following statement for order of reaction is not correct?

A

Order can be determined experimentally

B

Order of reaction is equal to sum of the powers of concentration terms in differential rate law.

C

It is not affected with the stoichiometric coefficient of the reactants

Order cannot be fractional.

Explanation

Q 12.

Correct4

Incorrect-1

Consider a reaction {tex} a G + b H \rightarrow {/tex} Products. When concentration of both the reactants {tex} G {/tex} and {tex} H {/tex} is doubled, the rate increases by eight times. However, when concentration of {tex} G {/tex} is doubled keeping the concentration of {tex} H {/tex} fixed, the rate is doubled. The overall order of the reaction is

A

0

B

1

C

2

3

Explanation


Q 13.

Correct4

Incorrect-1

Bombardment of aluminium by {tex} \alpha {/tex} -particle leads to its artificial disintegration in two ways, (i) and (ii) as shown. Products {tex} \mathrm { X } , \mathrm { Y } {/tex} and {tex} \mathrm { Z } {/tex} respectively are,

proton, neutron, positron

B

neutron, positron, proton

C

proton, positron, neutron

D

positron, proton, neutron

Explanation

Q 14.

Correct4

Incorrect-1

In the reaction,
{tex} \mathrm { P } + \mathrm { Q } \longrightarrow \mathrm { R } + \mathrm { S } {/tex}
The time taken for {tex} 75 \% {/tex} reaction of {tex} \mathrm { P } {/tex} is twice the time taken for {tex} 50 \% {/tex} reaction of {tex} \mathrm { P } {/tex}. The concentration of {tex} \mathrm { Q } {/tex} varies with reaction time as shown in the figure. The overall order of the reaction is

A

2

B

3

C

0

1

Explanation

Q 15.

Correct4

Incorrect-1

For the elementary reaction {tex} M \rightarrow N {/tex}, the rate of disappearance of {tex} M {/tex} increases by a factor of 8 upon doubling the concentration of {tex} M . {/tex} The order of the reaction with respect to {tex} M {/tex} is

A

4

3

C

2

D

1

Explanation