1
JEE Main 2025 (Online) 4th April Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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

A
$\mathrm{Ea}_2>\mathrm{Ea}_1>\mathrm{Ea}_3$
B
$\mathrm{Ea}_1>\mathrm{Ea}_3>\mathrm{Ea}_2$
C
$\mathrm{Ea}_3>\mathrm{Ea}_2>\mathrm{Ea}_1$
D
$\mathrm{Ea}_1>\mathrm{Ea}_2>\mathrm{Ea}_3$
2
JEE Main 2025 (Online) 4th April Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Half life of zero order reaction $\mathrm{A} \rightarrow$ product is 1 hour, when initial concentration of reactant is $2.0 \mathrm{~mol} \mathrm{~L}{ }^{-1}$. The time required to decrease concentration of A from 0.50 to $0.25 \mathrm{~mol} \mathrm{~L}^{-1}$ is :

A
0.5 hour
B
15 min
C
60 min
D
4 hour
3
JEE Main 2025 (Online) 4th April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

For $\mathrm{A}_2+\mathrm{B}_2 \rightleftharpoons 2 \mathrm{AB}$

$\mathrm{E}_{\mathrm{a}}$ for forward and backward reaction are 180 and $200 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively

If catalyst lowers $\mathrm{E}_{\mathrm{a}}$ for both reaction by $100 \mathrm{~kJ} \mathrm{~mol}^{-1}$.

Which of the following statement is correct?

A
Catalyst does not alter the Gibbs energy change of a reaction.
B
The enthalpy change for the reaction is $+20 \mathrm{~kJ} \mathrm{~mol}^{-1}$.
C
Catalyst can cause non-spontaneous reactions to occur.
D
The enthalpy change for the catalysed reaction is different from that of uncatalysed reaction.
4
JEE Main 2025 (Online) 4th April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Rate law for a reaction between $A$ and $B$ is given by

$$\mathrm{r}=\mathrm{k}[\mathrm{~A}]^{\mathrm{n}}[\mathrm{~B}]^{\mathrm{m}}$$

If concentration of $A$ is doubled and concentration of $B$ is halved from their initial value, the ratio of new rate of reaction to the initial rate of reaction $\left(\frac{r_2}{r_1}\right)$ is

A
$(\mathrm{n}-\mathrm{m})$
B
$2^{(\mathrm{n}-m)}$
C
$\frac{1}{2^{m+n}}$
D
$(\mathrm{m}+\mathrm{n})$
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