Praxis II: Chemistry Exam Prep

Answer: 1 M CaCl₂

In each of the solutions specified in the question, water is the solvent. Therefore, the solution with the highest boiling point is the solution that experiences the greatest boiling point elevation. Boiling point elevation is given by the formula (change in T_b) = (m)(k_b)(i). Each solution given in the question is of equal concentration, so the only factor affecting boiling point elevation is the number of ions dissolved in solution. CaCl₂ is the only compound that forms three ions per molecule when dissolved, and thus has the highest boiling point.