Question

What is the decreasing order of strength of the bases $OH^{-}, NH^{-}_{2}, H-C \equiv C^{-}$ 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_{2}CH^{-}_{2}$

Answer 1

Answer: (A)

The conjugate acids of the given bases are $H_2O, NH_3, C_2H_2, CH_3CH_3$. Their acidic strength are in the order $H_2O > C_2H_2 > NH_3 > CH_3CH_3$. A weak acid has a strong conjugate base.