Question

Calculate the mass of quick lime CaO obtained by heating 400g CaCO3 which is 85% pure

Answer 1

First we need to write a balanced chemical equation for the thermal decomposition taking place.

CaCO3→CaO+CO2

Next note the Mr values of each compound.

CaCO3=100g

CaO=56g

CO2=44g

The mass of pure CaCO3 present =

90/100×20kg

= 18kg

So now we will compare limestone and CaO

CaCO3:CaO

=0.1kg:0.056kg (The Mr values)

=18kg:x

Therefore, x=18kg×0.056kg/0.1kg

x=10.8kg

So a total of 10.8kg of CaO will be produced on heating.

Explanation:

Welcome