Nitric acid is not only a strong acid but also a strong oxidizing agent. In hot concentrated acid solution, the reaction with zinc is:
3 Zn(s) + 8 HNO3 ? 3 Zn(NO3)2(aq) + 2 NO(g) + 4 H2O
Calculate the mass of Zn(s) required to produce 4.2 g of NO(g) when the metal comes into contact with excess nitric acid.