Question
Question: An unknown alochol is treated with the “Lucas reagent” to determine whether the alcohol is primary, ...
An unknown alochol is treated with the “Lucas reagent” to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism
A
Secondary alcohol by SN1
B
Tertiary alcohol by SN1
C
Secondary alcohol by SN2
D
Tertiary alcohol by SN2
Answer
Tertiary alcohol by SN1
Explanation
Solution
The reaction of alcohol with lucas reagent is mostly an SN1 reaction and the rate of reaction is directly proportional to the carbocation stability formed in the reaction, since 3° R–OH forms 3° carbocation hence it will react fastest.