An aqueous KNO3 solution is made using 82.7 grams of KNO3, diluted to a total solution volume of 1.50 L. The density of this solution is 1.05 g/mL. What is the molality of this solution?

Answer 1

moles KNO3 = grams/molar mass
Solve for moles.

mass soln = volume x density = ??

mass H2O = total mass soln - mass solute.

molality = moles/kg solvent

Answer 2

so correct me if i may be wrong...

82.7gKNO3x1mol/101.11gKNO3=0.8179mol

1.5Lx1000ml/1Lx1.05g/1mL=1575g

1575-82.7=1492.3g

0.8179mol/1.4923kg=0.54808molal?

Answer 3

I agree but you have too many significant figures. You're allowed only 3.