We have to determine if the sample of a compound that contains 32.0 g of carbon and 8.0 g of hydrogen is methane or not.
The law of definite proportions states that a compound always contains its elements in a fixed ratio of masses. This ratio does not depend upon the source of compound or its method of preparation.
We have been provided with the information that methane forms when carbon and hydrogen combine in this ratio:
Carbon: 3 parts
Hydrogen: 1 part
Carbon: Hydrogen = 3:1
In methane, one part hydrogen combines with three parts carbon by mass.
If a sample of a compound containing only carbon and hydrogen contains 32.0 g of carbon and 8.0 g of hydrogen, could the sample be methane?