Question

The compound which give the most stable carbonium ion on dehydration is
A. `CH_(3)CH(CH_(3))CH_(2)OH`
B. `(CH_(3))_(3)COH`
C. `CH_(2)=CHCH_(2)CH_(2)OH`
D. `CH_(3)CHOHCH_(2)-CH_(3)`

Answer 1

Correct Answer - b
`underset("Tertiary")(CH_(3))_(3)C underset(" Alcohol")(-OH) underset(-H_(2)O)overset(+H^(+))rarr underset("more stable") underset(3^(@) "carbocation")((CH_(3))_(3) overset(+)(C))`
`CH_(2) = CH - CH_(2) - CH_(2)OH underset(-H_(2)O)overset(+H^(+))rarr CH_(2) = underset(("less stable"))underset(1^(@)"carbocation)(CH)- CH_(2) - overset(+)(C)H_(2)`
Increasing order of stability of carbocation is `1^(@)` carbocation `lt 2^(@)` carbocation `lt 3^(@)` carbocation