Question

What quantity of limestone (CaCO3) on heating will give 56kg of CaO?

Answer 1

Limestone (Chemical formula: CaCO3), upon heating, produces lime or calcium oxide (chemical formula: CaO) and carbon dioxide. The reaction can be represented by the following chemical equation:

CaCO_3 (s) + heat -> CaO (s) + CO_2 (g)

Here, 1 mole of limestone produces 1 mole of carbon dioxide and 1 mole of lime or calcium oxide.

The molar mass of limestone is 100 g (= mass of Ca + mass of C + 3 x mass of O = 40 + 12 + 3 x 16). Similarly, the molar mass of lime is 56 g.

Thus, we can also say that 100 g of limestone produces 56 g of lime.

Or, 1 g of lime is produced by 100/56 g limestone.

Thus, 56 kg of lime will be produced by 100/56 x 56 kg = 100 kg.

So, in order to obtain 56 kg of lime, we need to heat 100 kg of limestone.

Answer 2

Caco3_cao+co2

1 mole of caco3 gives 1 mole of cao

100gm caco3 gives 56 gm cao

100kg caco3 will give 56 kg cao