Question

at 20°C the concentration of O2 in the air is 8.65 x10-3 mol/L. what us the minimum volume of air in litres that are required to completely combust on
e litre of gasoline at 20°C? Assume the gasoline is octane which has a density of .703 g/mol at this temperature.

The balance equations is
C8H18 + 25/2 O2 => 8CO2 +9H2O
I REALLY NEED HELP WITH THIS QUESTION. I DON'T UNDERSATND IT AT ALL

Answer 1

Do you know how to do stoichiometry. That comes first.
Convert 1 L gasoline to grams with density; i.e., grams = volume x density.
Convert grams to mols gasoline; i.e., mols = grams/molar mass gasoline.

Use the coefficients in the balanced equation to convert mols gasoline to mols O2.
Them mols O2 needed = M x L. You have M and mols, solve for L.