Determine the mass of water that will be obtained from combustion of 200.g of propane.

Question

Consider the combustion of propane (44.1 g/mol) in the presence of excess oxygen.

Determine the mass of water that will be obtained from combustion of 200.g of propane.

C3H8 + 5O2 = 4H2O + 3CO2

Answer 1

C₃H₈ + 5O₂ ==> 3CO₂ + 4H₂O ... balanced equation

moles of C₃H₈ = 200. g x 1 mol/44.1 g = 4.535 moles

moles of H₂O produced = 4.535 mol C₃H₈ x 4 mol H₂O/1 mol C₃H₈ = 18.14 moles H₂O

mass H₂O produced = 18.14 moles H₂O x 18 g/mol = 327 g H₂O (to 3 sig. figs.)