In: Chemistry
Match the following aqueous solutions with the appropriate
letter from the column on the right. Assume complete dissociation
of electrolytes.
1. | 0.16 m | Zn(NO3)2 | A. | Highest boiling point | ||
2. | 0.22 m | AgCH3COO | B. | Second highest boiling point | ||
3. | 0.17 m | Mn(NO3)2 | C. | Third highest boiling point | ||
4. | 0.46 m | Urea (nonelectrolyte) | D. | Lowest boiling point |
Boiling point elevation depends on the solvent, of course, but we're assuming water, and upon the concentration of the solute and how many particles into which the solute breaks. Colligative properties like boiling point elevation, depend on the total number of particles in solution. The solvent used here is water. So elevation in boiling point will be above a boiling point of water for all solutions.
Kb is the same for all solution, so we can simply calculate m x i
Zn(NO3)2
i=3 m x i= 3 x 0.16= 0.48
B. | Second highest boiling point |
AgCH3COO
i=2 m x i = 2 x 0.22 = 0.44
D. | Lowest boiling point |
Mn(NO3)2
i=3 m x i = 3 x 0.17 = 0.51
A. | Highest boiling point |
Urea In case of urea , it neither dissociates nor associates so no of molecules after and before dissociation are same therefore i=1 for urea
m x i = 1 x 0.46 = 0.46
C. | Third highest boiling point |