Question

An aqueous solution is prepared by diluting 3.30 mL acetone (d = 0.789 g/mL) with water to a final volume of 75.0 mL. The density of solution is 0.993 g/mL . What are the molarity and molality of acetone in this solution?

Answer 1

Dear student,

mass of acetone: (3.30 mL) (0.789 g/mL) = 2.6037 g

moles of acetone: 2.6037 g / 58.0794 g/mol = 0.04483 mol

mass of solution: (75.0 mL) (0.993 g/mL) = 74.475 g

mass of water in the solution: 74.475 g - 2.6037 g = 71.8713 g

moles of water: 71.8713 g / 18.015 g/mol =

Molarity:

0.04483 mol / 0.0750 L = 0.598 M

Molality:

0.04483 mol / 0.0718713 kg = 0.624 m

Regards