Question

a solution has 10 moles of alcohol and 10 moles of water. what is the composition of the solution expressed in mole fraction? 

my teachers answer is:

Mole fraction of alcohol = 0.033

Mole fraction of H2O = 0.967

Answer 1

Mole fraction equals:

mole fraction = moles of solute / total moles of solution

From here:

mole fraction(alcohol) = 10 mol / 20 mol = 0.5

mole fraction (water) = 10 mol / 20 mol = 0.5

Since the answer does not equals the teacher's answer, it could be suggested that the data given is wrong. For example, 10 g or 10 ml of liquids are given.