Question

In $KH$, the oxidation number of hydrogen is:

• A. $+2$
• B. $+1$
• C. $0$
• D. $-1$
• E. $-2$

Answer 1

The correct option is D $-1$

In $KH$, the oxidation number of hydrogen is -1 and the oxidation number of $K$ is +1.
When $H$ is directly attached to strongly electropositive metals such as $K$, the $H$ atom is present in the form of hydride ion $\left(H^{-}\right)$ with an oxidation number of -1.