Question

The density of 3 molal solution of NaOH is 1.110 g/ml . Calculate the molarity of the solution.

Answer 1

Find Molarity , given Molality.

Molality = b = 3
mass density of Sodium Hydroxide solution = ρ = 1.110 gm/ml 
     ρ = 1.110 kg/Litre
M = Molar mass of Sodium Hydroxide NaOH = 40 = (23+16+1)
     = 40 gm/mole = 0.040 kg/mole
Molarity = c = ??

Formula for calculating Molarity given Molality:

          c = ρ * b / [1 + b M ]
             = 1.110 kg/L * 3 mole/kg  / [ 1 + 3 mole/kg * 0.040 kg/mole ]
             = 3.330 /(1.12) 
             = 2.97 Molar

Answer 2

Heya....

Kindly refer to above attachment...