Answer:
0.534
Explanation:
Mole fraction can be calculated using the formula:
Mole fraction = number of moles of solute ÷ number of moles of solvent and solute (solution).
In this question, solute is dimethyl ether while the solvent is methanol.
Mole (n) = mass (M) ÷ molar mass (MM)
Mole of solute (dimethyl ether) = 148.5 ÷ 46.07
= 3.22moles.
Mole of solvent (methanol) = 90 ÷ 32.04
= 2.81moles.
Total moles of solute and solvent = 3.22 + 2.81 = 6.03moles.
Mole fraction of dimethyl ether = number of moles of dimethyl ether ÷ number of moles of solution (dimethyl ether + methanol)
Mole fraction = 3.22/6.03
= 0.534