Differentiate molality and molarity in expressing solution concentration when considering freezing point depression, boiling point elevation, and osmotic pressure.

• A. Only molarity must be used as solution concentration in the calculation of freezing point depression, boiling point elevation, and osmotic pressure.
• B. Both molarity and molality can be accurately used in expressing solution concentration when computing for freezing point depression, boiling point elevation, and osmotic pressure.
• C. Molarity must be used to express solution concentration when calculating freezing point depression and boiling point elevation, while molality must be used in osmotic pressure calculations.
• D. Molality must be used when calculating freezing point depression and boiling point elevation, while molarity can be used for osmotic pressure calculations.

Answer: (D)