Question

The density of 3 molal solution of nios is 1.10 gram per ml calculate the molarity of the solution

Answer 1

A 3 molal solution is prepared by dissolving 3 moles (40 x 3 = 120g) of NaOH in 1000g 0f water.

Total mass of such solution containing 3 moles of the solute = 1000 +120 = 1120g

Density of this solution = 1.110g/ml

Density = mass/volume

Total volume of this solution = 1120/1.110 = 1009mL = 1.009L

Thus, 3 moles of NaOH are present in 1.009L of the solution.

So, no of moles present in 1L of the solution = 3 x 1/1.009 = 2.973