You have a sample of 63.5 g of C₂H₆. How many moles of C₂H₆ are in the sample?
Usually, when we are given the mass of a sample and we have to find the number of moles that are there, we have to use the molar mass of the compound. So, let's find the molar mass of C₂H₆. To do that, we have to look for the atomic masses of the elements that are present in the molecule.
C: 12.01 amu H: 1.01 amu
One molecule of C₂H₆ has 2 atoms of C and 6 atoms of H, so the molar mass will be:
molar mass of C₂H₆ = 2 * 12.01 + 6 * 1.01
molar mass of C₂H₆ = 30.08 g/mol