The activation energies of two reactions are ${E_a}$ and ${E'_a}$ with ${E_a} > {E'_a}.$ If the temperature of the reacting systems is increased from ${T_1}$ to ${T_2}$, predict which alternative is correct. $K'$ are rate constants at higher temperature. Assume $A$ being same for both the reactions:

$\frac{{{{K'}_1}}}{{{K_1}}} = \frac{{{{K'}_2}}}{{{K_2}}}$

${K_1} > {K_2}$ and ${K'_1} > {K'_2}$

$\frac{{{{K'}_1}}}{{{K_1}}} < \frac{{2{{K'}_2}}}{{{K_2}}}$

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JEE CHEMISTRY MCQ: CHEMICAL KINETICS

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Analyzing +4 | -1

The activation energies of two reactions are

{E_a}

and

{E'_a}

with

{E_a} > {E'_a}.

If the temperature of the reacting systems is increased from

{T_1}

{T_2}

, predict which alternative is correct.

K'

are rate constants at higher temperature. Assume

A

being same for both the reactions:

View answer and explanation

Correct option: B

{K_1} < {K_2}

and

{K'_2} < {K'_1}

The correct answer is B (

{K_1} < {K_2}

and

{K'_2} < {K'_1}

) because a higher activation energy implies a smaller rate constant, and the effect of temperature is more pronounced for reactions with higher activation energies.

More Questions from CHEMICAL KINETICS

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The reaction

\mathrm{A}_2+\mathrm{B}_2 \rightarrow 2 \mathrm{AB}

follows the mechanism

\begin{aligned} & {{\text{A}}_2}\mathop \rightleftharpoons \limits_{{{\text{k}}_{ - 1}}}^{{{\text{k}}_1}} {\text{A}} + {\text{A (fast) }} \\ & \mathrm{A}+\mathrm{B}_2 \xrightarrow{\mathrm{k}_2} \mathrm{AB}+\mathrm{B} \text { (slow) } \\ & \mathrm{A}+\mathrm{B} \rightarrow \mathrm{AB} \text { (fast) } \end{aligned}

The overall order of the reaction is: For the first order reaction with the rate constant

k

, which expression gives the rate half-life period?

(Initial\mathrm{ }conc.\mathrm{ } = a)

Which of the following is a zero order reaction? For a certain reaction involving a single reactant, it is found that

C_0 \sqrt{T}

is constant, where

C_0

is the initial concentration of the reactant and

T

is the half-life. What is the order of the reaction? Arrhenius equation is The energy of activation for an uncatalysed reaction is

100 \mathrm{~kJ/mol}.

Presence of a catalyst lowers the energy of activation by

75 \%

. The

\log _{10} \frac{K_2}{K_1}

of the ratio of rate constant of catalysed and uncatalysed reactions at

27^{\circ} \mathrm{C}

is?

Assume the frequency factor is same for both reactions. (Given

2.303 \times 8.314=19.147

)