Which of the following alkenes on hydrogen in the presence of an acid will give a primary alcohol ?

Options

A. But -`2`-ene
B. But-`1`-ene
C. Ethene
D. Propene

Answer

C

Explanation

Alkenes add water in the presence of an acid catalyst. Since addition followers Markovnikov's orientation and rearrangement often occur , ethyl alcohol is the only primary alcohol that can be synthesized from ethene
`CH_(3) = CH_(2) underset(H^(+)) overset(H_(2)O) rarr CH_(3)CH_(2)OH`
The reaction usually produces secondary and tertiary alcohols
`CH_(3)CH = CHCH_(3) underset(H^(+)) overset(H_(2)O) rarr CH_(3)underset(2^(@)"alcohol")(CH_(2))overset(OH)overset(|)(CH)CH_(3)`
`overset(or) (CH)_(3)CH_(2)CH = CH_(2)`
`CH_(3)CH = CH_(2) underset(H^(+))overset(H_(2)O)rarr CH_(3)underset(2^(@)"alcohol")overset(OH)overset(|)(CH)CH_(3)`