Boiling point of chloroform is 61 C. After addition of 5.0 g of a non-volatile solute to 20 g chloroform boils at 64.63 C. If kb = 3.63 K kg mol-1, what is the molecular weight of the solute?

• A. 320 g/mol
• B. 100 g/mol
• C. 400 g/mol
• D. 250 g/mol