Question

calculate molality for 0.5molar solution if density of that solution is 1gm/ml and solute is urea​

Answer 1

Molarity = 0.5

0.5 moles in 1000 ml solution

Density of solution = 1g/ml

Mass of solution = Volume x Density = 1000 x 1 = 1000g

Mass of solvent = Mass of solution - Mass of solute(urea) = 1000 - 30 = 970g

Molality = no. of moles/Mass of solvent in kg = 0.5/0.97 = 0.52 moles/kg