Question

When zinc oxide reacts with dilute nitric acid, zinc nitrate is produced. The equation for the reaction is: ZnO + 2HNO₃→ Zn(NO₃)₂ + H₂O. Use 0.200 mol of nitric acid reacts with excess zinc oxide. A mass of 15.3 g of zinc nitrate is produced. Calculate the percentage yield of zinc nitrate. [Mr of zinc nitrate = 189]

Answer 1

ZnO + 2HNO₃→ Zn(NO₃)₂ + H₂O

mol Zn(NO₃)₂ = mol ZnO = 0.2 (from the coefficient)

mass Zn(NO₃)₂ = 0.2 x 189 = 37.8 g (theorethical yield)

% yield = 15.3 : 37.8 x 100% = 40.48%