Predict the order of base strength of anions from the reactions given below.
`HC=CH+LiNH_(2)` hArr HC-= C^(-)Li^(+)+NH_(3)`
`HC-=C Li+H_(2)O hArr HC-=CH+LiOH`

Options

A. `OH^(-) lt HC-=C^(-) lt NH_(2)^(-)`
B. `HC-= C-lt OH^(-)lt NH_(2)^(-)`
C. `OH^(-)lt NH_(2)^(-) lt HC-=C^(-)`
D. `NH_(2)^(-) lt OH^(-) lt HC-=C^(-)`

Answer

A

Explanation

A stonger acid replaces a weaker acid from its salt. Hence, `HC -= CH gt NH_(3) (` acidic strength `)` and `H_(2)O gt HC -=CH. `
`:. H_(2)OgtHC -= CH gt NH_(3)(` acidic strength order `)`
Hence, for conjugate bases `: OH^(-)HC-=C^(-)ltNH_(2)^(-)`( basic strength order)