if theres a mixture of components we can calculate the mole fraction
mole fraction can be calculated as follows
mole fraction of component = [tex] \frac{number of moles of component}{total number of moles of all components } [/tex]
number of moles of ethanol - 3.00 mol
total number of moles in mixture - 3.00 + 5.00 = 8.00 mol
mole fraction of ethanol = [tex] \frac{3.00 mol}{8.00 mol } [/tex]
mole fraction of ethanol is 0.375