Calculate the amount of substance and the mass of copper oxide that can react with nitric acid with a mass of 12.6 grams.

Given:

m (HNO3) = 12.6 g

To find:

n (CuO) -?

m (CuO) -?

Decision:

CuO + 2HNO3 = Cu (NO3) 2 + H2O, – we solve the problem, relying on the composed reaction equation:

1) Find the amount of nitric acid that has reacted:

n (HNO3) = m: M = 12.6 g: 63 g / mol = 0.2 mol

2) We compose a logical expression:

If 1 mol of CuO requires 2 mol of HNO3, then x mol of CuO requires 0.2 mol of HNO3, then x = 0.1 mol.

3) Find the mass of copper oxide required for the reaction to proceed:

m (CuO) = n * M = 0.1 mol * 80 g / mol = 8 g.

Answer: n (CuO) = 0.1 mol; m (CuO) = 8 g.