IAT IISER2026ChemistryHaloalkanes and Haloarenes
Which one is an INCORRECT statement with regard to the following reaction?
Options
- AThe reaction rate decreases upon changing the solvent from ethyl alcohol to 1:1 mixture of ethyl alcohol and w
- BThe reaction rate does not change upon increasing the concentration of hydroxide ion.
- CThe rate determining step is the dissociation of tert -butylbromide.
- DThe reaction rate is proportional to the concentration of tert -butylbromide.
Correct answer
A. The reaction rate decreases upon changing the solvent from ethyl alcohol to 1:1 mixture of ethyl alcohol and w
Step-by-step solution
The given reaction is the nucleophilic substitution of a tertiary alkyl halide (tert-butyl bromide) to form a tertiary alcohol (tert-butyl alcohol). Tertiary alkyl halides undergo substitution via the S_N1 mechanism due to steric hindrance which prevents the S_N2 mechanism, and the formation of a stable tertiary carbocation intermediate. The S_N1 mechanism proceeds in two steps: Dissociation of tert-butyl bromide to form a tert-butyl carbocation and a bromide ion. This is the slow, rate-determining step. Attack of