1.
For the redox reaction xP4+yHNO3H3PO4+NO2+H2Ox\mathrm{P_4} + y\mathrm{HNO_3} \rightarrow \mathrm{H_3PO_4} + \mathrm{NO_2} + \mathrm{H_2O}, upon balancing with whole number coefficients: