Sidney P. answered 05/02/21
Astronomy, Physics, Chemistry, and Math Tutor
In this stoichiometry, first convert moles of the reactant to moles of product using the coefficients in the balanced reaction, then multiply by molar mass of the product. It's basically dimensional analysis.
1) (7.7 mol CuO) * (1 mol N2 / 3 mol CuO) * (28g N2 / 1 mol N2) = 71.9g N2.
2) (10.2 mol HNO3) * (4 mol H2O / 8 mol HNO3) * (18g H2O / 1 mol H2O) = 91.8g H2O.