Identify the species involved in the reaction: nitrite ion (\(\mathrm{NO_2^-}\)), aluminum metal (\(\mathrm{Al}\)), ammonia gas (\(\mathrm{NH_3}\)), and aluminate ion (\(\mathrm{AlO_2^-}\)).
Write the unbalanced chemical equation: \(\mathrm{NO_2^- (aq)} + \mathrm{Al (s)} \rightarrow \mathrm{NH_3 (g)} + \mathrm{AlO_2^- (aq)}\).
Balance the atoms of each element one at a time, starting with aluminum and nitrogen, since aluminum forms \(\mathrm{AlO_2^-}\) and nitrogen is in both \(\mathrm{NO_2^-}\) and \(\mathrm{NH_3}\).
Include water molecules (\(\mathrm{H_2O}\)) and possibly hydrogen ions or hydroxide ions if the reaction occurs in aqueous solution, to balance hydrogen and oxygen atoms properly.
Check that the total charge is balanced on both sides of the equation, ensuring the number of electrons lost equals the number of electrons gained, confirming the redox balance.