a) $$\text{11HNO}_3 + \text{I}_2 \rightarrow \text{2HIO}_3 + \text{11NO} + \text{4H}_2\text{O}$$
б) $$4NH_3+5O_2 \rightarrow 4NO + 6H_2O$$
в) $$3Mg+N_2\rightarrow Mg_3N_2$$