Question

Calcium carbonate decomposes, on heating , to form calcium oxide and carbon dioxide. When 10 g of calcium carbonate is decomposed completely, then `5.6 g` of calcium of oxide is formed. Calculate the mass of carbon dioxide formed. Which law of chemical combination will you use in solving this problem ?

Answer 1

This problem is to be solved by using the law of conservation of mass in chemical reactions. In this reaction, calcium carbonate is the reactant whereas calcium oxide and carbon dioxide are products. Now, from the law of conservation of mass we have :
Mass of product = Mass of reactants
or `underset("oxide")("Mass of calcium") + underset("dioxide")("Mass of carbon") = underset("carbonate")("Mass of calcium")`
So, `5.6 + underset("dioxide")("Mass of carbon") = 10`
And, `underset("dioxide")("Mass of carbon") = 10-5.6`
`= 4.4 g`
Thus, the mass of carbon dioxide formed is `4.4 g`