Question

15 ml of a mixture of C2H4 & CH4 after oxidation with O2 gave 20 ml of CO2.Express the composition of the mixture in volume measure.
a. 10 ml C2H4 , 5 ml CH4
b. 5 ml C2H4 , 10 ml CH4

Answer 1

assuming everything is in the gas phase and excess O2, then the total number of C in the reactants must equal the total number of C in the products (gas volumes are proportional to molar amounts). if C2H4 is x, then CH4 is 15-x.

C from C2H4 would be 2x and C from CH4 would be 15-x

Assuming complete combustion (H2O is the only other product)
2x + 15 - x = 20
x = 5 ml of C2H4, 10 ml of CH4

Answer 2

tnx a lot!!