Which of the following is the least acidic?

Options

A. `H_2O`
B. `CH_3CH_2OH`
C. `CH-=CH`
D. `NH_3`

Answer

D

Explanation

Order of relative acidity
`H-OHgtH-ORgtH-C-=CHgtH-NH_2` order of relative basicity
`overline(O)Hltoverline(O)Rltoverline(C)-=CHltoverline(N)H_2`
Note that though N is more electronegative than C atom the basic character of `overline(N)H_3` predominates over its acidic character.