Question

What is the molality of 1 m solution of sodium nitrate if its density is 1.25 g cc?

Answer 1

The total mass of the solution is:

1000 cm^3 times 1.25 g/cm^3 = 1250 g

How much water is in the solution:

1250 g minus 85.0 g = 1165 g

The molality would be :

1.00 mol / 1.165 kg = 0.86 m

Answer 2

The total mass of the solution is:

1000 cm^3 x 1.25 g/cm^3 = 1250 g

How much water is in the solution:

1250 g-85.0 g = 1165 g

The molality would be :no. of moles of solute/mass of solvent in (kg)

1000/0.1165=8.583 m.