How much oxygen is required to oxidize 4.0 g of calcium?

Calcium enters into an oxidation reaction with oxygen. This reaction is described by the following equation:
Ca + ½ O2 = CaO;
During the reaction, one oxygen atom is attached to the calcium atom. In this case, one molecule of calcium oxide is synthesized.
Let’s define the chemical (molar) amount of calcium.
To do this, divide the available weight of elemental calcium by the weight of 1 mole of this substance.
M Ca = 40 grams / mol; N Ca = 4/40 = 0.1 mol;
To oxidize such an amount of calcium, 2 times less oxygen is required.
Let’s calculate its volume.
To do this, multiply the available volume of oxygen gas by the volume of 1 mole of gas (22.4 liters).
V O2 = 0.1 x 22.4 = 2.24 liters;