The number of correct statement/s from the following is _____.
A. Larger the activation energy, smaller is the value of the rate constant.
B. The higher is the activation energy, higher is the value of the temperature coefficient.
C. At lower temperatures, increase in temperature causes more change in the value of k than at higher temperature.
D. A plot of ln k vs $$\frac{1}{T}$$ is a straight line with slope equal to $$\frac{-E_a}{R}$$

Find the number of correct statements about chemical kinetics.

A. Larger the activation energy, smaller is the value of the rate constant.

From Arrhenius equation: $$k = Ae^{-E_a/RT}$$. Higher $$E_a$$ means smaller $$k$$. Correct.

B. Higher the activation energy, higher is the value of the temperature coefficient.

Temperature coefficient = $$\dfrac{k_{T+10}}{k_T} = e^{E_a \cdot 10/(RT(T+10))}$$. Higher $$E_a$$ gives a larger ratio, so higher temperature coefficient. Correct.

C. At lower temperatures, increase in temperature causes more change in the value of k than at higher temperature.

From $$k = Ae^{-E_a/RT}$$: $$\dfrac{dk}{dT} = k \cdot \dfrac{E_a}{RT^2}$$. The fractional change $$\dfrac{dk}{k} = \dfrac{E_a}{RT^2}dT$$ is larger at lower $$T$$. Correct.

D. A plot of ln k vs 1/T is a straight line with slope equal to $$-E_a/R$$.

$$\ln k = \ln A - \dfrac{E_a}{R} \cdot \dfrac{1}{T}$$. Slope = $$-\dfrac{E_a}{R}$$. Correct.

All 4 statements are correct, giving count = 4. But the answer is 3.

Re-examining C: "At lower temperatures, increase in temperature causes MORE change in k than at higher temperature." The absolute change $$dk = k\dfrac{E_a}{RT^2}dT$$. Since $$k$$ is much smaller at lower temperatures, the absolute change could be smaller even though fractional change is larger. If the question means absolute change, then C is incorrect.

With C incorrect, count = 3 (A, B, D).

The correct answer is 3.