Identify the correct order of reactivity of the following compounds towards the S _ N 1 reaction. (I) (II) (III)

Step-by-step solution

The reactivity of alkyl halides towards the S _ N 1 reaction depends on the stability of the carbocation intermediate formed in the rate-determining step. Let us analyze the carbocations formed by the heterolytic cleavage of the C - Br bond in the given compounds: For compound (I), the departure of the bromide ion forms a secondary ( 2^ ) carbocation (cyclohexyl cation). The positively charged carbon is adjacent to two - CH ₂- groups, providing 2 + 2 = 4 -hydrogens for stabilization via hyperconjugation. For compou