If 0.500 mol of each of the following solutes is dissolved in 2.0 L of water, which will cause the greatest increase in the boiling point of the solution?

Question

A. KI
B. CO2
C. Na2SO4
D. NaCl

Answer 1

delta T = i*Kb*m
Look at this logically. m = mols/kg solvent; therefore, m is constant for all of these. Kb, the boiling point constant is a constant for all of these. Therefore, the ONLY variable is i.
i = 2 for A
i = 1 for B
i = 3 for C.
i = 2 for D.
i is the van't Hoff factor.
So the solute with the largest delta T, when added to the normal boiling point of water will have the highest boiling point.