The mole fraction of a non-electrolyte (MM 40.0 g/mol) in a saturated aqueous solution is 0.310. What is the molality of the solution?

The molality of non-electrolyte is 24.69 m

Explanation:

We are given:

Mole fraction of saturated aqueous solution = 0.310

This means that 0.310 moles of non-electrolyte is present.

Moles of water (solvent) = 1 - 0.310 = 0.690 moles

To calculate the mass from given number of moles, we use the equation:

Moles of water = 0.690 moles

Molar mass of water = 18 g/mol

Putting values in above equation, we get:

To calculate the molality of solution, we use the equation:

Where,

= Moles of solute (non-electrolyte) = 0.310 moles

= Mass of solvent (water) = 12.42 g

Putting values in above equation, we get:

Hence, the molality of non-electrolyte is 24.69 m