Chemical reactions can be categorized as oxidation-reduction (redox) reactions, where electrons are transferred between reactants. In the following redox reaction, sodium iodide (NaI) is reduced and nitrogen trichloride (NIII) is oxidized:

NaI + e- → Na0 (reduction)

NIII - 1 e- → NIV (oxidation)

On the other hand, sodium nitrite (NaNO2) can act as both an oxidizing agent and a reducing agent. When NaNO2 undergoes a redox reaction, it can donate electrons and become a reducing agent, or accept electrons and become an oxidizing agent.

To write a balanced chemical equation for the reaction between NaNO2 and sodium (Na) and nitrogen dioxide (NO2).

Word Equation

sodium nitrite → sodium + nitrogen dioxide

Next, we convert the word equation into a chemical equation by assigning stoichiometric coefficients to the reactants and products:

c1 NaNO2 → c2Na + c3NO2

We then balance the equation by ensuring that the number of atoms of each element is the same on both sides of the equation. We start by setting an arbitrary coefficient, usually 1, and solve for the remaining coefficients:

c1 = 1

c2 = 1

c3 = 1

Substituting these values into the chemical equation, we obtain the balanced equation:

NaNO2 → Na + NO2

In summary, sodium nitrite (NaNO2) can act as both an oxidizing agent and a reducing agent in a redox reaction. When NaNO2 reacts with sodium and nitrogen dioxide, the balanced chemical equation is 

NaNO2 → Na + NO2.