Complete combustion of 2.60 g of a hydrocarbon produced 8.36 g of CO2 and 2.85 g of H2O. What is the empirical formula for the hydrocarbon? Insert subscripts as necessary.

Answer 1

Moles of C = 8.36 g CO2 x 1 mol CO2/44 g x 1 mol C/mol CO2 = 0.19 moles of C

Moles of H = 2.85 H2O x 1 mol H2O/18 g x 2 mol H/mol H2O = 0.32 moles of H

Dividing both by 0.19 we obtain...

1 mol C

1.6667 mol H

Multiplying both by 3 we obtain...

3 mol C

5 mol H

Empirical formula = C₃H₅