Nitric acid is produced commercially by the Ostwald process, represented by the following equations:
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
2NO(g) + O2(g) → 2NO2(g)
3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g)
What mass of NH3 must be used to produce 1.0 × 106 kg HNO3 by the Ostwald process? Assume 100% yield in each reaction, and assume that the NO produced in the third step is not recycled.