Question

An unknown compound contains only C, H and O. Combustion of 5.60g of this compound produced 11.18g of CO2 and 4.58g of H2O. Find the Empirical formula.

Answer 1

Mass of CO2:
C=[11.18/(12.011+2x15.9994)]*12.011
and the moles
mass of H2O :
H=[4.58/(1.00794x2+15.9994)]/2*1.00794

Then subract: C-H=O (in grams.). O/15.9994=moles of O

11.18gCO2 x 12g/44g = 3.04gC
So 3.04C x I mol/12g = 0.254