Question

Analyze the generalized rate data for the reaction
$RX+N{u}^{-}⟶$ Nucleophilic Product

$\begin{array}{cccc}\text{S. No.}& \text{[RX]Substrate}& \text{[Nu] Attacking species}& \text{Rate of reaction}\left(M{s}^{-1}\right)\\ 1.& 0.10M& 0.10M& 1.2\times {10}^{-4}\\ 2.& 0.20M& 0.10M& 2.4\times {10}^{-4}\\ 3.& 0.10M& 0.20M& 2.4\times {10}^{-4}\\ 4.& 0.20M& 0.20M& 4.8\times {10}^{-4}\end{array}$
Which of the following is the most appropriate potential energy v/s reaction coordinate diagram of the reaction on the basis of above data analysis?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

From the data given, it is found that the reaction is first order w.r.t. $RX$ and first order w.r.t. $N{u}^{-}$. So overall order of reaction is 2 i.e. reaction follows $S_{N}2$ mechanism. Since $S_{N}2$ reactions proceed through a single transition state and are exothermic. Hence, the correct option is (b).