Calculate molality, molarity and mole fraction of KI if the density of 20% (mass) aqueous KI is 1.202 g/mL

Basis: 1 L of the substance.

(1.202 g/mL) x (1000 mL) = 1202 g

mass solute = (1202 g) x 0.2 = 240.2 g

mass solvent = 1202 g x 0.8 = 961.6 g

moles KI = (240.2 g) x (1 mole / 166 g) = 1.45 moles

moles water = (961.6 g) x (1 mole / 18 g) = 53.42 moles

1. Molality = moles solute / kg solvent

= 1.45 moles / 0.9616 kg = 1.5 m

2. Molarity = moles solute / L solution

= 1.45 moles / 1 L solution = 1.45 M

3. molar mass = mole solute / total moles

= 1.45 moles / (1.45 moles + 53.42 moles) = 0.0264