Chapter 3, Problem 3.95P

Hydrocarbon mixtures are used as fuels, (a) How many grams of ${\text{CO}}_{\text{2}}\left(g\right)$ are produced by the combustion of 200. g of a mixture that is 25.0% ${\text{CH}}_{\text{4}}$ and 75.0% ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}$ by mass? (b) A 252-g gaseous mixture of ${\text{CH}}_{\text{4}}$ and ${\text{C}}_{\text{3}}{\text{H}}_{\text{8}}$ bums in excess ${\text{O}}_{\text{2}}$, and 748 g of ${\text{CO}}_{\text{2}}$ gas is collected. What is the mass % of ${\text{CH}}_{\text{4}}$ in the mixture?