Identify the correct order of reactivity for the S _ N 1 reaction of the following compounds: (i) (ii) (iii)

Step-by-step solution

The rate of an S _ N 1 reaction depends on the stability of the carbocation formed and the leaving group ability. Since the alkyl group is the same (tert-butyl) in all three compounds, the intermediate formed is the tert-butyl carbocation in each case. Thus, the reactivity is determined solely by the leaving group ability. A better leaving group is a weaker base, which corresponds to a stronger conjugate acid. The leaving groups in the given compounds are: (i) Triflate ion ( CF ₃ SO ₃⁻ ) (ii) Chloride ion ( Cl ⁻ )