The formula between Mole fraction and Molality is m=
Xsolute
Xsolvent
×
1000
Msolvent
m= molality, Xsolute = Mole fraction of solute, Xsolvent = Mole fraction of solvent, Msolvent = Molar mass of solvent Here solute is methyl alcohol (CH3OH) and solvent is water (H2O). Here water is solvent because question says solution is aqueous. Assume mole fraction of methyl alcohol =X So mole fraction of water =1−X and given molality (m)=5.2 Msolvent =18 (as molar mass of H2O=18 ) ∴5.2=