Combustion Analysis Extra Problems Key

1 Combustion Analysis Problems (optional): Key 1. A hydrocarbon fuel is fully combusted with g of oxygen to yield g of carbon dioxide and g of water. Find the empirical formula for the hydrocarbon. g CO2 1 mol g CO21 mol C1 mol CO2= mol C 1 mol g H2O 1 mol g H2O2mol H1 mol H2O= mol H mol H CH 2. After Combustion with excess oxygen, a g of a petroleum compound produced g of carbon dioxide and of water. A previous Analysis determined that the compound does not contain oxygen. Establish the empirical formula of the compound. g CO2 1 mol g CO21 mol C1 mol CO2= mol C mol g H2O 1 mol g H2O2mol H1 mol H2O= mol H mol H1 mol C 5=5 mol mol 5= 12 mol H C5H12 3.

2 In the course of the Combustion Analysis of an unknown compound containing only carbon, hydrogen, and nitrogen, g of carbon dioxide and g of water were measured. Treatment of the nitrogen with H2 gas resulted in g NH3. The complete Combustion of g of the compound needed g of oxygen. What the compound s empirical formula? g CO2 1 mol g CO21 mol C1 mol CO2= mol C 2 mol g H2O 1 mol g H2O2mol H1 mol H2O= mol H 5 mol g NH3 1mol g NH31 mol N1 mol NH3= mol N mol N C2H5N 4. g of a biochemical substance containing only carbon, hydrogen, and oxygen was burned in an atmosphere of excess oxygen. Subsequent Analysis of the gaseous result yielded g carbon dioxide and g of water.

3 Determine the empirical formula of the substance. mass C= g CO2 1 mol g CO21 mol C1 mol g C1 mol C= g Cmass H= g H2O 1 mol g H2O2mol H1 mol g H1 mol H2O= g Hmass O= g g C g H= Omol C = g C 1 mol g C= mol C 1 mol Cmol H= g H 1 mol g H= mol H 2 mol Hmol O= g O 1 mol O= mol H mol O CH2O 5. g of oxygen was used to completely react with a sample of a hydrocarbon in a Combustion reaction. The reaction products were g of carbon dioxide and g of water. Ascertain the empirical formula of the compound. g CO2 1 mol g CO21 mol C1 mol CO2= mol C mol g H2O 1 mol g H2O2mol H1 mol H2O= mol H mol H1 mol C 5=5 mol mol H 5 8 mol H C5H8