Question

In ${\mathrm{Na}}_2\mathrm{O}$, what is the oxidation state of oxygen?

Answer 1

Step 1: Find the oxidation number

• The oxidation number is also known as the oxidation state, is the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.
• Sodium is an alkali metal and having $+1$ oxidation state.
• In .${\mathrm{Na}}_2\mathrm{O}$ two sodium atoms are present.
• The total charge of ${\mathrm{Na}}_2\mathrm{O}$ is zero.
• Let the oxidation number of $\mathrm{O}$ be $x$.
• Therefore, the oxidation number of $\mathrm{O}$ is-

$$\begin{gathered} 2\times 1+x=0 \\ 2+x=0 \\ x=-2 \end{gathered}$$

• Hence, the oxidation number of $\mathrm{Na}$ is $-2$.