Question

The oxidation state of $C$ in formaldehyde is

• A. $-2$
• B. $+2$
• C. $0$
• D. $+4$

Answer 1

Answer: (C)

Effective charge on a compound is zero.
Therefore, assuming oxidation state of $C$ as x,
${\left(CH\right)}_{2}O:x\times 1+2\times 1+(-2)=0$