Question

Hydride ion $\left(H^{-}\right)$ is a stronger base than hydroxide ion $\left(O{H}^{-}\right)$. In the light of the above fact, which of the following reactions will take place if $NaH$ is dissolved in water?

• A. $H_{\left(aq\right)}^{-}+H_{2}O\to H_3{O}_{\left(aq\right)}^{+}$
• B. $H_{\left(aq\right)}^{-}+H_{2}O\to O{H}^{-}+H_2$
• C. $H_{\left(aq\right)}^{-}+H_{2}O\to H_3{O}^{-}$
• D. $H_{\left(aq\right)}^{-}+H_{2}O\to$ No reaction

Answer 1

Answer: (B)

It is given that hydride ion is a stronger base than $O{H}^{-}$. Now, if $NaH$ is dissolved in water, the following reaction occurs.

As $H^{-}$ will act as stronger base than ${OH}^{-}$ ion, it will accept a proton from water to give $H_2$ and ${OH}^{-}$.

$H^{-}+H^{+}{OH}^{-}\to H_2+{OH}^{-}$