Chemical Kinetics Part 3

Concept:Arrhenius equation relates the rate constant $k$ to activation energy $E_a$ and temperature $T$.Explanation:The Arrhenius equation is $k = A e^{-E_a / (RT)}$, where $A$ is the pre-exponential factor and $R$ is the gas constant.In base‑10 logarithm form: $\log k = \log A - \frac{E_a}{2.303R} \cdot \frac{1}{T}$.Now evaluate each statement:Statement A: $e^{-E_a/(RT)}$ represents the fraction of molecules with kinetic energy equal to or greater than $E_a$, not less. So A is incorrect.Statement B: Lower $E_a$ gives a larger value of $e^{-E_a/(RT)}$, which increases $k$, making the reaction faster. This is correct.Statement C: As a common empirical rule mentioned in NCERT, a $10^\circ$C rise in temperature approximately doubles the reaction rate for many reactions. Correct.Statement D: A plot of $\log k$ vs $1/T$ gives a straight line with slope $-\frac{E_a}{2.303R}$, not $-\frac{E_a}{R}$. The slope $-\frac{E_a}{R}$ applies to a plot of $\ln k$ vs $1/T$. So D is incorrect.Therefore, the correct statements are B and C only.Answer:Option C: B and C Only.