1. Chapter 13 Solutions

2. The curve describes the solubility properties of
A liquid
An ionic solid
A covalent solid
A gas
A gas or liquid
1.0
2.0
Solubility mM 15 30 45 60
Temperature ( C)

3. The curve describes the solubility properties of
A liquid
An ionic solid
A covalent solid
A gas
A gas or liquid
1.0
2.0
Solubility mM 15 30 45 60
Temperature ( C)

4. Considering the substances given below, predict which will be soluble in water.1 2 3
2, 3
1, 2, 3

5. Considering the substances given below, predict which will be soluble in water.1 2 3
2, 3
1, 2, 3

6. When concentration is expressed in units of ________ , changing temperature will affect the solution concentration.
Molality
Molarity
ppm
Molarity and molality
Molarity, molality, and ppm

7. When concentration is expressed in units of ________ , changing temperature will affect the solution concentration.
Molality
Molarity
ppm
Molarity and molality
Molarity, molality, and ppm

8. Predict which aqueous solution will have the lowest freezing point.
0.25 m C2H5OH
0.15 m CaCl2
0.20 m NaCl
0.15 m NH4NO3
0.15 m Na3PO4

9. Predict which aqueous solution will have the lowest freezing point.
0.25 m C2H5OH
0.15 m CaCl2
0.20 m NaCl
0.15 m NH4NO3
0.15 m Na3PO4

10. Arrange the aqueous solutions according to increasing boiling point.
AlCl3 < KNO3 < Na2SO4
Na2SO4 < AlCl3 < KNO3
Na2SO4 < KNO3 < AlCl3
KNO3 < AlCl3 < Na2SO4
KNO3 < Na2SO4 < AlCl3
0.10 m Na2SO4
0.15 m AlCl3
0.20 m KNO3

11. Arrange the aqueous solutions according to increasing boiling point.
AlCl3 < KNO3 < Na2SO4
Na2SO4 < AlCl3 < KNO3
Na2SO4 < KNO3 < AlCl3
KNO3 < AlCl3 < Na2SO4
KNO3 < Na2SO4 < AlCl3
0.10 m Na2SO4
0.15 m AlCl3
0.20 m KNO3

12. Which polyethylene solution will produce the largest osmotic pressure?
Assume that all solutions use the same solvent and have the same concentration.

13. Which polyethylene solution will produce the largest osmotic pressure?
Assume that all solutions use the same solvent and have the same concentration.

14. From weakest to strongest, rank the following solutions in terms of solvent–solute interactions: NaCl in water, butane (C4H10) in benzene (C6H6), water in ethanol.
NaCl in water < C4H10 in C6H6 < water in ethanol
Water in ethanol < NaCl in water < C4H10 in C6H6
C4H10 in C6H6 < water in ethanol < NaCl in water

15. Correct Answer: NaCl in water < C4H10 in C6H6 < water in ethanol
Water in ethanol < NaCl in water < C4H10 in C6H6
C4H10 in C6H6 < water in ethanol < NaCl in water
Butane in benzene will have only weak dispersion force interactions. Water in ethanol will exhibit much stronger hydrogen-bonding interactions. However, NaCl in water will show ion–dipole interactions because NaCl will dissolve into ions.

16. At a certain temperature, the Henry’s law constant for N2 is 6
At a certain temperature, the Henry’s law constant for N2 is 6.0  104 M/atm. If N2 is present at 3.0 atm, what is the solubility of N2?
6.0  104 M
1.8  103 M
2.0  104 M
5.0  105 M

17. Correct Answer: 6.0  104 M 1.8  103 M 2.0  104 M 5.0  105 M
Henry’s law,
Sg = (6.0  104 M/atm)(3.0 atm)
Sg = 1.8  103 M

18. Determine the mass percentage of hexane in a solution containing 11 g of butane in 110 g of hexane.
9.0 %
10. %
90.%
91 %

19. Correct Answer: 9.0 % 10. % 90.% 91 %  Thus, 110 g (110 g + 11 g)
mass of
component in
solution
mass % of
component = 
100
total
mass of
solution
Thus,
110 g
(110 g + 11 g)
 100 = 91%

20. If 3. 6 mg of Na+ is detected in a 200
If 3.6 mg of Na+ is detected in a 200. g sample of water from Lake Erie, what is its concentration in ppm?
7.2 ppm
1.8 ppm
18 ppm
72 ppm

21. Correct Answer: 7.2 ppm 1.8 ppm 18 ppm 72 ppm   mass of component in
solution
ppm of
component =  10 6
total
mass of
solution
3.6 mg
0.0036 g =  10 6 = 18
ppm
200. g
200. g

22. What is the molality of 6. 4 g of methanol (CH3OH) dissolved in 50
What is the molality of 6.4 g of methanol (CH3OH) dissolved in 50. moles of water?
0.040 m
0.22 m
0.064 m
0.11 m

23. Correct Answer:
0.040 m
0.22 m
0.064 m
0.11 m

24. How many moles of solute are there in 240 g of a solution that is 5
How many moles of solute are there in 240 g of a solution that is 5.0% glucose (C6H12O6) by mass?
0.033 moles
0.067 moles
0.10 moles
0.12 moles
0.20 moles

25. Correct Answer: 0.033 moles 0.067 moles 0.10 moles 0.12 moles
5.0 % glucose means 5.0 g glucose/100 g solution
(5.0 g glucose/100 g solution)(240 g solution) = 12 g
(12 g glucose)  (1 mol glucose/180 g glucose) = moles glucose

26. At a certain temperature, water has a vapor pressure of 90. 0 torr
At a certain temperature, water has a vapor pressure of 90.0 torr. Calculate the vapor pressure of a water solution containing mole sucrose and 0.72 mole water.
9.0 torr
10. torr
80. torr
81. torr
90. torr

27. Pi = (0.72 mol/[0.72 + 0.080 mol])(90.0 torr)
Correct Answer:
9.0 torr
10. torr
80. torr
81. torr
90. torr  P = P i i
total
Pi = XiPtotal
Pi = (0.72 mol/[ mol])(90.0 torr)
Pi = (0.90)(90.0 torr) = 81. torr

28. Ethanol normally boils at 78. 4°C
Ethanol normally boils at 78.4°C. The boiling point elevation constant for ethanol is 1.22°C/m. What is the boiling point of a 1.0 m solution of CaCl2 in ethanol?
77.2°C
79.6°C
80.8°C
82.1°C
83.3°C

29. =  T K m Correct Answer: b b 77.2°C 79.6°C 80.8°C 82.1°C 83.3°C
The increase in boiling point is determined by the molality of total particles in the solution. Thus, a 1.0 m solution of CaCl2 contains 1.0 m Ca2+ and
2.0 m Cl for a total of 3.0 m. Thus, the boiling point is elevated 3.7°C, so it is 78.4°C + 3.7°C = 82.1°C.

30. At 300 K, the osmotic pressure of a solution is 0. 246 atm
At 300 K, the osmotic pressure of a solution is atm. What is its concentration of the solute?
1.0 M
0.50 M
0.25 M
0.10 M

31. ( ) Correct Answer: n  = RT = MRT V 1.0 M 0.50 M 0.25 M 0.10 M
M = (0.246 atm)/[( L-atm/mol-K)(300K)]
M = (0.246 atm)/( L-atm/mol) = 1.0 M

32. Which of the following is not an example of a colloid?
Fog
Smoke
Paint
Milk
Carbonated water

33. Correct Answer: Fog Smoke Paint Milk Carbonated water
Carbonated water is a solution; all the other substances in the list are excellent examples of colloids.