JEE Advanced 2017 · Paper 2 · Chemistry Q10

ChemistryMultiple correct+4 / -2Question 28 of 54

In a bimolecular reaction, the steric factor P was experimentally determined to be 4.5. The correct option(s) among the following is(are)

The activation energy of the reaction is unaffected by the value of the steric factor

Experimentally determined value of frequency factor is higher than that predicted by Arrhenius equation

Since P = 4.5, the reaction will not proceed unless an effective catalyst is used

The value of frequency factor predicted by Arrhenius equation is higher than that determined experimentally

Answer and worked solution

Official answer: A, B

In collision theory $k=PZe^{-E_a/RT}$ , with $P$ the steric factor.

(A) $P$ multiplies the pre-exponential term only; $E_a$ is unchanged. True.
(B) $P=\dfrac{A_{exp}}{A_{theory}}=4.5>1$ , so the experimental frequency factor is larger than predicted. True.
(D) says the opposite. False.
(C) A large $P$ does not stop the reaction. False.

(A), (B)

Topics:Collision theory Arrhenius equation

JEE Advanced 2017 · Paper 2, Chemistry question 10