When 70 grams of calcium carbonate is decomposed, calcium oxide is formed.

When 70 grams of calcium carbonate is decomposed, calcium oxide is formed. Determine the mass of the oxide formed and determine the molar mass.

The thermal decomposition reaction of calcium carbonate is described by the following chemical reaction equation:

CaCO3 = CaO + CO2 ↑;

Let’s determine the chemical amount of calcium carbonate. To do this, we divide its weight by the mass of 1 mole of the substance.

M CaCO3 = 40 + 12 + 16 x 3 = 100 grams / mol;

N CaCO3 = 70/100 = 0.7 mol;

The same molar amount of calcium oxide and carbon dioxide will theoretically be synthesized.

Let’s calculate the mass of calcium oxide. To do this, multiply the amount of the substance by the weight of 1 mole of the substance.

M CaO = 40 + 16 = 56 grams / mol;

m CaO = 0.7 x 56 = 39.2 grams;