Question

How many moles of H2O are required to produce 4.5 moles of HNO3 in the reaction of; 3NO2 + H2O ? 2HNO3 + NO

Answer 1

the equation tells you that each mole of H2O produces 2 moles of HNO3

so, 4.5/2 = 2.25 moles of H2O will produce 4.5 moles of HNO3