Colligative Properties
Useful Equations:
Solvent
acetic acid
acetone
benzene
camphor
carbon tetrachloride
chloroform
ether
ethyl alcohol
ethylene glycol
methyl alcohol
formic acid
napthalene
phenol
toluene
water
M = Mol
L
Normal
Freezing Point
o
( C)
16.6
- 95.4
5.5
178.8
- 23.0
- 63.5
- 116.3
- 117.3
- 13.5
- 97.8
8.3
80.2
40.9
- 94.5
0.0
Molal Freezing
Point Constant
o
Kf ( C/molal)
- 3.90
Normal Boiling
Point (oC)
117.9
56.2
80.1
207.4
76.7
61.2
34.6
78..3
197.2
64.5
100.8
217.7
181.8
110.7
100.0
- 4.90
- 39.7
- 1.79
- 2.77
- 6.8
- 7.40
- 1.86
Molal Boiling
Point Constant
o
Kb ( C/molal)
3.07
1.71
2.53
5.61
5.03
3.63
2.02
1.22
0.83
3.56
3.56
3.33
0.512
Solutions Worksheet
Answer each of the following questions in the space provided.
concentration molarity molality saturated unsaturated supersaturated
1. _________________________ is the concentration of a solution expressed as the number of moles of
solute dissolved in each liter of solution.
2. A ______________________ solution contains as much solute as can possibly be dissolved under
existing conditions of temperature and pressure
3. The amount of solute in a given amount of solvent or solution is the ___________________ of a
solution.
4. A solution that contains more solute particles than are needed to form a saturated solution is
_______________________.
5. The ________________________ of a solution is the number of moles of solute dissolved in each
kilogram of solvent.
6. A solution that has less than the maximum amount of solute that can be dissolved is called a(n)
_____________________ solution.
7. Give the number of particles (“i”)that each compound will make in solution.
NH3
______
C2H5OH
______
AlCl3
CO2
______
SiO2
______
Al(NO3)3 _____
LiOH
______
Si2Cl6 ______
CH3OCH2CH3 ______
______
C6H12
_______
BaBr2 ______
Na3PO3
_______
KHSO4 ______
NH4Br
_______
Solve each of the following problems as directed. Show all your work.
8. What is the molarity of the solution formed by mixing 0.20 mol of sodium hydroxide with
enough water to make 150 ml of solution?
9. How much potassium bromide, in grams, should be added to water to prepare 0.50 L of solution with a molarity
of 0.125 M?
10. What is the molality of a solution of chlorine and water is 0.0362 m. This solution contains 3500 g of water.
How much chlorine in grams, was used to prepare this solution?
11. What is the molarity of the solution produced when 145 g of sodium chloride is dissolved in sufficient water to
prepare 2.75 L of solution?
12. HOW is 3.00 L of a 1.90 M solution of sodium hydroxide prepared?
13. HOW do you prepare 250 mL of a 6.0 M solution from 18M sulfuric acid?
14. HOW do you prepare 100.0 mL of a 2.0 M solution from 12 M hydrochloric acid?
15. To what volume should 25 ml of 15 M nitric acid be diluted to prepare a 3.0 M solution?
16. What is the molality of a solution produced using 15.2 g of Calcium chloride and 345 g of methanol (CH 3 OH)?
17. In order to prepare a 0.523 m aqueous solution of potassium iodide, how many grams of potassium iodide must
be added to 2.00 kg of water?
Colligative WBP
18. What is the molarity of a solution that contains 55 grams of copper (II) chloride dissolved in 1500 mL of
water?
0
19. What would the boiling point of a 0.75 m BeF2 (electrolyte) solution be? Kb (H2O) = 0.51 C/m.
20. Rank the following three solutions from lowest to highest melting point: 0.25 m barium hydroxide, 0.45 m
sugar, 0.65 m sodium hydroxide.
21. Why does increasing the solute concentration decrease the melting point?
22. You experimentally determined that 45.750 g of Naphthalene melts at 80.25 C. You then mixed 1.340g of
magnesium fluoride with the 45.750 g of Naphthalene to give a new melting point of 70.52 C. Determine
the Kf Value .
23. If I add 45 grams of sodium chloride to 500 grams of water, what will the melting and boiling points be of
0
0
the resulting solution? Kb (H2O) = 0.52 C/m and Kf (H2O) = 1.86 C/m.
24. Which solution will have a higher boiling point: A solution containing 105 grams of sucrose (C12 H22 O11) in
500 grams of water or a solution containing 35 grams of sodium chloride in 500 grams of water?
25. When a 30.0-g sample of an unknown nonelectrolyte is dissolved in 600. g of benzene, the
freezing point of the resulting solution is 3.77 oC. The freezing point of pure benzene is
5.48 oC and Kf for benzene is 5.12 C/m. Calculate the molar mass of the unknown compound.
26. A solution is prepared by dissolving 34.1 g of MgCl2 375.0 g of water. If the boiling point
increases by 1.305°C, what is the observed van’t Hoff factor? The boiling point elevation
constant for water is 0.512 °C/m.