Carbon dioxide produced by combustion of methane with a mass of 160 g occupies the same volume as in the combustion of propane

Carbon dioxide produced by combustion of methane with a mass of 160 g occupies the same volume as in the combustion of propane. How much propane is burnt?

Given:
m (CH4) = 160 g
V1 (CO2) = V2 (CO2)

To find:
V (C3H8) -?

Decision:
1) Write the reaction equations:
CH4 + 2O2 => CO2 ↑ + 2H2O;
C3H8 + 5O2 => 3CO2 ↑ + 4H2O;
2) Calculate the molar mass of CH4:
M (CH4) = Mr (CH4) = Ar (C) * N (C) + Ar (H) * N (H) = 12 * 1 + 1 * 4 = 16 g / mol;
3) Calculate the amount of CH4:
n (CH4) = m (CH4) / M (CH4) = 160/16 = 10 mol;
4) Calculate the volume of CO2:
V (CO2) = n (CO2) * Vm = 10 * 22.4 = 224 l;
5) Determine the volume of C3H8:
V (C3H8) = V (CO2) / 3 = 224/3 = 74.7 l.

Answer: The volume of C3H8 is 74.7 liters.