42.6 g Cu are combined with 84.0 g of HNO₃ according to the reaction:
3 Cu + 8 HNO₃ → 3 Cu(NO₃) ₂ + 2 NO + 4 H₂O
Which reagent is limiting and how many grams of Cu(NO₃) ₂ are produced?

Question

Quizplus · Accepted Answer

The limiting reagent is HNO₃. The molar mass of Cu is 63.55 g/mol, so 42.6 g of Cu is 0.67 mol. The molar mass of HNO₃ is 63.01 g/mol, so 84.0 g of HNO₃ is 1.33 mol. According to the balanced equation, 8 moles of HNO₃ react with 3 moles of Cu. Therefore, HNO₃ is the limiting reagent. The molar mass of Cu(NO₃)₂ is 187.56 g/mol, and 1.33 mol of HNO₃ will produce 0.5 mol of Cu(NO₃)₂, which is 93.8 g.

426 G Cu Are Combined with 84