Question

A solution is made by mixing equal masses of methanol, CH4O, and ethanol, C2H6O. Determine the mole fraction of each component to at least three significant figures.

Answer 1

pick a convenient mass, like 1000g, for each of the components.
Figure out how many moles this mass is for each (from their molecular weights).
Add them up to get total number of moles, then use the individual mole #s to get their individual mole fractions.