Calculate the mass and amount of calcium substance reacted with 32g of oxygen.

1.Let’s find the amount of oxygen by the formula:

n = m: M.

M (O2) = 32g / mol.

n = 32 g: 32 g / mol = 1 mol.

2. Let’s compose the reaction equation.

Let’s find the quantitative ratios of substances.

2Ca + O2 = 2CaO.

According to the reaction equation, there is 2 mol of calcium for 1 mole of oxygen. Substances are in quantitative ratios of 2: 1.

The amount of calcium substance will be 2 times more than the amount of oxygen.

n (Ca) = 2n (O2) = 1 × 2 = 2 mol.

3.Let’s find the mass of calcium by the formula:

m = n × M,

M (Ca) = 40 g / mol.

m = 2 mol × 40 g / mol = 80 g.

Answer: 80 g.