Question

What is the decreasing order of strength of the bases $O{H}^{-},{{NH}_2}^{-},H-C\equiv C^{-}$ and ${CH}_3{CH}_2^{-}$?

• A. ${CH}_3{CH}_2^{-}>{{NH}_2}^{-}>H-C\equiv C^{-}>{OH}^{-}$
• B. $H-C\equiv C^{-}>{CH}_3{CH}_2^{-}>{{NH}_2}^{-}>{OH}^{-}$
• C. ${OH}^{-}>{{NH}_2}^{-}>H-C\equiv C^{-}>{CH}_3{CH}_2^{-}$
• D. ${{NH}_2}^{-}>H-C\equiv C^{-}>{OH}^{-}>{CH}_3{CH}_2^{-}$

Answer 1

The correct option is A ${CH}_3{CH}_2^{-}>{{NH}_2}^{-}>H-C\equiv C^{-}>{OH}^{-}$

Strong base has its weak conjugate acid.

Strength of conjugate acid: $H_{2}O>CH\equiv CH>N{H}_3>C{H}_{3}C{H}_3$.

So strength of base follow an reverse order as:$C{H}_3{CH}_2^{-}>{NH}_2^{-}>CH\equiv C^{-}>{OH}^{-}$