How many grams of calcium oxide is formed by the interaction of calcium with oxygen in a volume of 11.2 liters?

Let’s write the equation of the reaction of formation of calcium oxide.

2Ca + O2 = 2CaO.

Knowing the volume of oxygen, we find the number of mol.

n (O2) = V / Vm = 11.2 L / 22.4 mol / L = 0.5 mol.

From the reaction it follows that two times more calcium oxide was formed.

n (CaO) = 2 • n (O2) = 2 • 0.5 = 1 mol.

The mass of the oxide is.

m (CaO) = n • Mr = 1 mol • 56 g / mol = 56 g.