Question

Acid catalysed dehydration of t-butanol is faster than that of n-butanol because:

• A. tertiary carbocation is more stable than primary carbocation
• B. primary carbocation is more stable than tertiary carbocation
• C. t-butanol has a higher boiling point
• D.
  • rearrangement takes place during dehydration of t-butanol.
    

Answer 1

Answer: (A)

tertiary carbocation is more stable than primary carbocation

Alcohol $+H_{2}S{O}_4\to$ Alkene

The dehydration reaction is an elimination reaction that goes via carbocation formation. Since tertiary carbocations are most stable due to + Inductive effect of alkyl groups, then is the secondary and least stable is primary.

Therefore the reactivity of alcohol is governed by the stability of carbocation that follows the order as

Tertiary > secondary > primary

Hence, acid catalysed dehydration of t-butanol is faster than that of n-butanol because tertiary carbocation formed by t-butanol is more stable than primary carbocation formed by n-butanol.