Question

Molality of 2% weight aqueous solution of sodium chloride is

Answer 1

Assume that we have 100 g of the solution.

Then we have 2 g of NaCl and 98 g of water.

The formula for molality is
Molality = moles of salute/kilograms of
solvent
Moles of NaCl
= 2g NaCl. X 1mol NaCl/58.45 g Nacl
= 0.0342 mol NaCl
Mass of water 98 g = 0.098 kg
Molality = 0.0342/0.098
= 0.349 mol/kg