A 1.078 g sample of a compound containing only carbon,hydrogen,and oxygen is burned in an excess of dioxygen,producing 2.451 g CO₂ and 1.003 g H₂O.What mass of oxygen is contained in the original sample?

Question

Quizplus · Accepted Answer

The mass of oxygen in the original sample can be found by subtracting the masses of carbon and hydrogen (found in the CO2 and H2O produced) from the total mass of the sample. The mass of carbon in CO2 is found by the ratio of the molar masses (12/44) times the mass of CO2 produced, and the mass of hydrogen in H2O is found by the ratio of the molar masses (2/18) times the mass of H2O produced. Subtracting these from the total sample mass gives the mass of oxygen in the sample.

A 1078 G Sample of a Compound Containing Only Carbon,hydrogen,and Oxygen