Question

Given, 100 cc, each of water gas and oxygen are ignited and the resultant mixture of gases cooled to room temperature. Calculate the composition of the resultant mixture. [Water gas contains $CO$ and ${{H}_{2}}$ in equal ratio]

Answer 1

When water gas and oxygen are mixed together then the two products formed are carbon dioxide and water. So first write the balanced chemical equation and then the composition of the mixture can be calculated.

Complete answer:
The question says that the water gas and oxygen are ignited to form a mixture and the water gas is a mixture of carbon monoxide and hydrogen gas. So there are three reactants in the reaction. So the products in this reaction will be carbon dioxide and water. The balanced equation will be:
$CO+{{H}_{2}}+{{O}_{2}}\to C{{O}_{2}}+{{H}_{2}}O$
So in this reaction, one mole of carbon monoxide, one mole of hydrogen, and one mole of oxygen produce one mole of carbon dioxide and one-mole water. According to Gay Lussac’s law, one mole of gas is equal to the one volume of the gas.
So from the above equation, one volume of carbon monoxide requires one volume of oxygen. Since the mixture is 100 cc, so 50 cc of carbon monoxide will require 50 cc of oxygen atoms. So 50 cc of water gas and 50 cc of oxygen will produce 50 cc of carbon dioxide.
So the volume of oxygen is 50 cc and the volume of carbon dioxide is 50 cc.

Note:
The volume of the water is negligible because the water formed in the reaction is in liquid form. The volume of the gases is only calculated according to Gay Lussac’s law.