Question

Arrange $N{H}_4^{+},H_{2}O,H_3{O}^{+},HF$ and $O{H}^{-}$ in increasing order of acidic nature:

• A. $H_3{O}^{+}<N{H}_4^{+}<HF<O{H}^{-}<H_{2}O$
• B. $N{H}_4^{+}<HF<H_3{O}^{+}<H_{2}O<O{H}^{-}$
• C. $O{H}^{-}<H_{2}O<N{H}_4^{+}<HF<H_3{O}^{+}$
• D. $H_3{O}^{+}>HF>H_{2}O>N{H}_4^{+}>O{H}^{-}$

Answer 1

Answer: (C)

Among the given species, correct order of increasing acidic strength is: $O{H}^{-}<H_{2}O<N{H}_4^{+}<HF<H_3{O}^{+}$ $O{H}^{-}$ is basic (i.e., it tends to gain a proton) and hence is least acidic. $H_{2}O$ is neutral species. $H_3{O}^{+}$ is most acidic as it readily loose proton.