Question

When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced.

1. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen?
2. Which law of chemical combinations will govern your answer?

Answer 1

1. 3.0 g of carbon combines with 8.0 g of oxygen to give 11.0 g of carbon dioxide. If 3 g of carbon is burnt in 50 g of oxygen, then 3 g of carbon will react with 8 g of oxygen. The remaining 42 g of oxygen will be left unreacted. In this case, also, only 11 g of carbon dioxide will be formed.
2. The above answer is governed by the law of constant proportions. According to the law of constant proportions, a chemical compound always contains the same elements combined together in the same proportion by mass.