Assuming that the hydrocarbon only contains hydrogen and carbon, then it will have the formula CxHy where x and y represents the number of carbon and hydrogen atoms, respectively. We proceed as follows:
CxHy + ((x+y/2)/2)O2 = xCO2 + y/2H2O
1.9584 g H2O ( 1 mol / 18.02 g ) ( 2 mol H / 1 mol H2O ) = 0.0272y
y = 8 mol H
3.5927 g CO2 ( 1 mol / 44.01 g ) ( 1 mol C / 1 mol CO2 ) = 0.0272x
x = 3 mol C
C3H8 = 44.11 g / mol
