The mole fraction of a product is the number of moles of the product divided by the total number of moles of the solution.
Here moles of methanol = 6.0 moles
Moles of solution = 6.0 moles of methanol + 3.0 moles of water = 9.0 moles of solution
Mole fraction of methanol = 6.0 / 9.0 = 0.67
Answer: 0.67
