A 3.391 g sample of a compound containing only carbon,hydrogen,and oxygen is burned in an excess of dioxygen,producing 6.477 g CO₂ and 3.978 g H₂O.What mass of oxygen is contained in the original sample? A)1.178 g B)1.4899 g C)3.086 g D)2.499 g E)0.5874 g

Question

Quizplus · Accepted Answer

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

A 3391 G Sample of a Compound Containing Only Carbon,hydrogen,and Oxygen