20 g of nh4cl is added to 13.9 g of water. calculate the molality of the solution.

Molar mass NH4Cl = 53.491 g/mol

number of moles solute:

n = m / mm

n = 20 / 53.491

n = 0.373 moles

solvent in kg:

13.9 / 1000 = > 0.0139 kg

Therefore:

m = moles / volume

m = 0.373 / 0.0139

=> 26.83 molal