Question

What is the oxidation number of H in ${\mathrm{H}}_2\mathrm{O}$?

Answer 1

Oxidation number

Oxidation number denotes the oxidation state of an element in a compound ascertained according to a set of rules formulated on the basis that electron pair in a covalent bond belongs entirely to a more electronegative element.

Calculating the oxidation number of Hydrogen(H) in ${\mathrm{H}}_2\mathrm{O}$:

The oxidation state of Oxygen(O) = -2

Consider the oxidation state of Hydrogen(H) = x

Now,

$$\begin{gathered} 2\left(\mathrm{x}\right)-2=0 \\ \mathrm{x}=+1 \end{gathered}$$

Hence, the oxidation number of Hydrogen in ${\mathrm{H}}_2\mathrm{O}$ is $+1$, and Oxygen is $-2$.