Question

Observe the following reactions:

The order of reactivity of x, y, z towards S\textsubscript{N}1 reaction is:

• A. x>z>y
• B. x>y>z
• C. y>x>z
• D. y>z>x

Hint:

In SN1, consider both carbocation stability and leaving group ability to predict reactivity.

Answer 1

The Correct Option is C

Step 1: Understand SN\textsubscript{1 mechanism}
SN\textsubscript{1} is a two-step mechanism involving carbocation formation. Better leaving group and more stable carbocation = faster reaction. Step 2: Compare leaving groups
\[ \text{Cl}^-<\text{Br}^-<\text{SOCl}_2 (forms intermediate) \] Step 3: Reactivity order
Chloride is a better leaving group in polar protic solvents than bromide. Alcohol treated with SOCl\textsubscript{2} is slower due to its mechanism. \[ \Rightarrow \text{Order: } y>x>z \] %Quicktip