The combustion of ethane:

Question

2 C2H6 (g) + 7 O2 (g) ---> 4 CO2 (g) + 6 H2O (g)

At the same temperature and pressure, what is the maximum volume in liters of carbon dioxide that can be obtained from 15.9 L of ethane and 52.3 L of oxygen?

Answer 1

You can take a short cut when dealing with all gases. The short cut is that you can deal directly with volume and not convert to mols. But to complicate matters this is a limiting reagent problem. First convert L ethane to L CO2.
L CO2 = 15.9 L C2H6 x ( 4 mols CO2/2 mols C2H6) = ?
Then do the same with 52.3 L O2.
L CO2 = 52.3 L O2 x (4 mols CO2/7 mols O2) = ?
It is likely that the two values for volume CO2 will not agree; obviously one of them is wrong. In limiting reagent problems the smaller values is ALWAYS the correct one.

Answer 2

29.88 L