Question

In the reaction CH${}_3$OH $\to$ HCOOH, the number of electrons that must be addad to the right is :

• A. 4
• B. 3
• C. 2
• D. 1

Answer 1

The correct option is A 4

Assign oxidation no.s for each atom in equation.

$C$ has changed its oxidation number from $-2$ to $+2$

$(+2)-(-2)=4$

${CH}_{3}OH\rightleftharpoons HCOOH+4e^{-}$

So, $4$ electrons are to be added on right side.