Find the volume of CO2 that is formed by heating 100g of limestone containing 20% of impurities.

The decomposition reaction of limestone (calcium carbonate) is described by the following equation:

CaCO3 = CaO + CO2;

In the course of the reaction, 1 molecule of calcium oxide and 1 molecule of carbon dioxide are synthesized from 1 molecule of calcium carbonate.

Let’s calculate the amount of substance contained in 100 grams of chalk containing 20% ​​impurities.

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

N CaCO3 = 100 x 0.8 / 100 = 0.8 mol;

The same amount of carbon dioxide will be synthesized. Let’s calculate its volume.

To do this, multiply the amount of substance by the volume of 1 mole of gas.

V CO2 = 0.8 x 22.4 = 17.92 liters;

m CaO = 56 x 0.25 = 14 grams;