Calculate the amount of lime obtained by heating 400 kg of limestone.

The correct option is B 224 kg
The chemical equation for decomposition of limestone can be written as:

$CaC{O}_3\to CaO+C{O}_2$

100 kg of $CaC{O}_3$ produces 56 kg of $CaO$.

400 kg of $CaC{O}_3$ produces $\frac{56\times 400}{100}$ $=224$ kg.

Hence, option C is correct.