Question

Find the oxidation number of carbon in HCHO.

Answer 1

Let the oxidation number of $C$ be $x$

The oxidation number of $O$ and $H$ are $-2$ & $+1$ respectively.

$\therefore 1+x+1-2=0$

$\therefore x=0$

Therefore, the oxidation number of $C$ in $HCHO$ is zero.