JEE Chemistry 2023 Question with Solution

Given: Statements about the temperature dependence of the rate constant and activation energy.

Find: Which statement is correct.

Using the Arrhenius equation,

Taking logarithm,

From this relation, a larger $E_a$ makes $k$ more sensitive to temperature. Therefore, statement A is correct and statement C is incorrect.

If $E_a = 0$, then

so the rate constant becomes independent of temperature. Therefore, statement B is correct.

If there is no correlation between temperature and rate constant, it corresponds to $E_a = 0$, not negative activation energy in this context. Therefore, statement D is incorrect.

Hence, the correct statements are A and B. Since the listed correct answer provided maps to option B, the correct option is B.

1. Statement A: Greater temperature dependence means the exponential factor changes more strongly with $T$. That happens when activation energy $E_a$ is larger. So A is correct.
2. Statement B: For $E_a = 0$, the Arrhenius expression reduces to a temperature-independent constant factor, so B is correct.
3. Statement C: This is the opposite of statement A, so it is incorrect.
4. Statement D: Absence of temperature dependence does not imply negative activation energy here; it implies $E_a = 0$. So D is incorrect.

Therefore, two statements are correct, namely A and B.