A 10 g sample of a mixture of Cu and CuO was reduced by hydrogen gas, and 1.8 g of water was formed. Determine the mass of Copper in the original mixture.
- 2 g
- 2 g
- 8 g
- 5 g
📝 Detailed explanation
CuO + H₂ → Cu + H₂O.Only CuO reacts.
Moles H₂O = 1.8 / 18 = 0.1 mol.
Moles CuO = 0.1 mol.
Mass CuO = 0.1 × 80 = 8 g.
Mass Cu = 10 - 8 = 2 g.