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Q.
The oxidation state of $C$ in formaldehyde is
NTA AbhyasNTA Abhyas 2020
Solution:
Effective charge on a compound is zero.
Therefore, assuming oxidation state of $C$ as x,
$\left(CH\right)_{2}O:x\times 1+2\times 1+\left(\right.-2\left.\right)=0$