Find the molarity of this solution.

Question

In 20.0 degree Celsius, a 0.258 m aqueous solution of C6H12O6 (glucose) has a density of 1.017 g/mL. Find the molarity of this solution.

Answer 1

0.258 m glucose = 0.258 moles glucose / kg H2O

mass glucose = 0.258 mols x 180 g / mol = 46.4 g glucose

mass H2O = 1kg = 1000 g

Total mass of solution = 1000 g + 46.4 g = 1046.4 g

Volume of solution = 1046.4 g x 1 ml / 1.017 g = 1029 ml = 1.029 L

Molarity = moles glucose / liter of solution

Molarity = 0.258 mols / 1.029 L = 0.251 M