ANSWER
The oxidation state of nitrogen in NaNO2 is +3
EXPLANATION
Given information
[tex]\text{ Chemical formula }\rightarrow\text{ NaNO}_2[/tex]To find the oxidation state of nitrogen in NaNO2, follow the steps below
Step 1: Write NaNO2 in the ionic form
[tex]\text{ NaNO}_2\text{ }\rightarrow\text{ Na}^+\text{ + N + O}_2^{2-}[/tex]From the above reaction, you will see that the oxidation number of sodium is +1, and the oxidation number of oxygen is -2.
Step 2: Let the oxidation state of nitrogen be x
Add the oxidation numbers together and equate all to zero
[tex]\begin{gathered} +1\text{ + x + 2\lparen-2\rparen = 0} \\ +1\text{ + x + \lparen-4\rparen = 0} \\ +1\text{ + x - 4 = 0} \\ +1\text{ - 4 + x = 0} \\ -3\text{ + x = 0} \\ Add\text{ 3 to the both sides} \\ -3\text{ + 3 + x = 0 + 3} \\ x\text{ = 3} \end{gathered}[/tex]Hence, the oxidation state of nitrogen in NaNO2 is +3
