# Question a3c21

Apr 18, 2017

The molar mass of $C {H}_{4} = 12 + 4 \times 1 = 16$
and the molar mass of $C {O}_{2} = 12 + 2 \times 16 = 44$

#### Explanation:

All gasses have the same molar volume, so we may say that the mass ratio is $m \left(C {O}_{2}\right) \div m \left(C {H}_{4}\right) = 44 \div 16 = 11 \div 4$

The mass percentage : m%(CO_2)=11/(11+4)xx100%=73%#

(rounded figures have been used)