Question

Which of the given pair of $S_{N}1$ reaction would you expect to proceed faster?

• A. 3°-alcohol > 2°-alcohol
• B. 3°-alcohol < 2°-alcohol
• C. 3°-alcohol = 2°-alcohol
• D. None of these

Answer 1

The correct option is A 3°-alcohol > 2°-alcohol

The rate of $S_{N}1$ reaction depends on the stability of the carbocation formed. More stable carbocation will proceed faster by $S_{N}1$ mechanism.
Tertiary carbocation is stable than secondary which in turn is stable than primary.
Hence, tertiary alcohol reacts faster than secondary alcohol towards $S_{N}1$ reaction.