Question

Which of the following statements about boiling point elevation is not true?
I. Addition of a nonvolatile solute raises the vapor pressure of a solution. Therefore, a higher temperature will be needed to produce boiling.
II. The molal concentration of solute particles dissolved in the solvent is an important factor in determining the molal boiling point elevation constant.
III. The identity of solute particles dissolved in the solvent is an important factor in determining the molar boiling point elevation constant.

• A. I only
• B. II only
• C. I and II only
• D. II and III only
• E. I, II and III

Answer 1

Answer: (C)

I and II only

I. The non-volatile solute does not create vapour pressure, so adddition of non-volatile solute does not increase the vapour pressure of the solution.

II. Molal boiling point elevation constant is independent to the molar concentration of the solute.