Question

The relative order of basicity of conjugate bases is :

• A. $O{H}^{-}<O{R}^{-}<HC\equiv C^{-}$
• B. $O{H}^{-}<HC\equiv C^{-}<O{R}^{-}$
• C. $HC\equiv C^{-}<O{H}^{-}<O{R}^{-}$
• D. $HC\equiv C^{-}<O{R}^{-}<O{H}^{-}$

Answer 1

The correct option is A $O{H}^{-}<O{R}^{-}<HC\equiv C^{-}$

Weaker the acid, stronger is the conjugate base.

$H_{2}O>R-OH>CH\equiv CH$

Water is more acidic than alcohols and alcohols are more acidic than alkynes.

Alkynes are very weak acids hence their basicity will be highest.

So the order of basicity of conjugate base is :

$O{H}^{-}<O{R}^{-}<HC\equiv C^{-}$

Option A is correct.