JEE MAIN - Chemistry (2025 - 4th April Evening Shift - No. 2)

Consider the following plots of $\log$ of rate constant $\mathrm{k}(\log \mathrm{k})$ vs $\frac{1}{\mathrm{~T}}$ for three different reactions. The correct order of activation energies of these reactions is :

JEE Main 2025 (Online) 4th April Evening Shift Chemistry - Chemical Kinetics and Nuclear Chemistry Question 5 English

$\mathrm{Ea}_2>\mathrm{Ea}_1>\mathrm{Ea}_3$
$\mathrm{Ea}_1>\mathrm{Ea}_3>\mathrm{Ea}_2$
$\mathrm{Ea}_3>\mathrm{Ea}_2>\mathrm{Ea}_1$
$\mathrm{Ea}_1>\mathrm{Ea}_2>\mathrm{Ea}_3$

Explanation

$$\begin{aligned} & \mathrm{K}=\mathrm{A} \mathrm{e}^{-\mathrm{EaRT}} \\ & \operatorname{logk}=\log \mathrm{A}-\frac{\mathrm{Ea}}{2.303 \mathrm{RT}} \end{aligned}$$

For graph between logk with $\frac{1}{\mathrm{~T}}$

$$\mid \text { Slope of curve } \left\lvert\,=\frac{\mathrm{Ea}}{2.303 \mathrm{R}}\right.$$

From given graph

Magnitude of slope $\Rightarrow(2)>(1)>(3)$

Hence $\mathrm{Ea}_2>\mathrm{Ea}_1>\mathrm{Ea}_3$

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