Hydrazine, N2H4, is an oily liquid used as a rocket fuel. It can be prepared in water by oxidizing ammonia with hypochlorite ions:
2 NH3(g) + ClO−(aq) → N2H4(aq) + Cl−(aq) + H2O(l)
When 35.0 g of ammonia reacted with excess hypochlorite ion, 25.2 g of hydrazine was produced. What is the percent yield of hydrazine?