A 1.56 g sample of copper reacts with a mass of oxygen to form 1.95 g of the metal oxide. In another experiment, the molar mass of the metal oxide is calculated to be 79.545 grams/mol. What is the molecular formula of the metal oxide?

The molecular formula of the metal oxide is CuO

Explanation:

Molar mass 79.545 g/m belongs to CuO

This is the reaction:

2Cu (s) + O₂ (g) → 2CuO (s)

2 mol of Cu produce 2 mol of CuO

Molar mass Cu = 63.5 g/m

Mass / Molar mass = 1.56 g / 63.5 g/m →0.0245 m

0.0245 mol of Cu produce 0.0245 mole of CuO

Molar mass CuO = 79.545 g/m

Mol. Molar mass = mass

0.0245 m. 79.545 g/m = 1.95 g