Ch. 12 Solutions
Chapter Review Problems.
1. Tyndall Effect
a. The Tyndall effect is the scattering of light by colloidal particles dispersed in a transparent medium.
b. The ability to see a headlight beam as it shines through fog.
2. Use the Tyndall effect. Shine a beam through the mixture. If it is a solution, no light scattering will be observed.
If it is a colloid the light will be scattered. If a suspension, the light will be blocked, and the particles will settle.
You could also look at the mixtures. If particles visible with the naked eye or a magnifying lens, then it is a
suspension. If particles are visible with a microscope, it is a colloid. If no particles are visible with even a
microscope, then it is a solution.
3. A suspension consists of particles that are large enough to be viewed under a magnifying glass and microscope.
4. No, a solution is any homogeneous mixture and can be gas/gas or solid/solid or gas/solid or solid/gas.
5. An electrolyte is an ionic compound, which produces ions when dissolved in water, and therefore can conduct
electricity. A nonelectrolyte is a molecular compound, which does not produce ions when dissolved in water,
and therefore cannot conduct electricity.
6. Equilibrium
a. Solution equilibrium is the state in which the opposing forces of dissolution and crystallization of the
solute are equal or the same.
b. The factors affecting equilibrium point of a solution are the chemical nature of the solute, the chemical
nature of the solvent, the temperature, and for gases, the pressure.
7. Saturation
a. A saturated solution is one that contains the maximum possible amount of dissolved solute in the given
amount of solvent at the given temperature and pressure.
b. Some solute will not dissolve and be visible in the mixture when it is at saturation.
c. An unsaturated solution contains less solute than the solvent can contain at the given conditions.
8. Solubility
a. In simplest terms; solubility is the ability to be dissolved. More complete; it is the amount of solute that
is dissolved in a given amount of solvent at equilibrium under specific conditions.
b. The amount of solvent, the temperature, and for gasses, the amount of pressure.
9. General solubility rule:
a. Like dissolves like
b. Polar solutes dissolve in polar solvents, and nonpolar solutes dissolve in nonpolar solvents
10. Gas solubility
a. The solubility of a gas in a liquid is directly proportional to the pressure of the gas. If the pressure goes
up, the solubility goes up; if the pressure goes down, the solubility goes down.
b. Henry’s Law
c. If the pressure has increased, the solubility will increase, so more gas can be dissolved.
d. The warmer pop will effervesce (release gas) more. The pressure change is the same for both, so that
solubility change is the same for both bottles. The warmer soda pop will have a lower solubility so more
gas will come out of solution when it is opened.
11. Solubility
a. Approximately 80 g
b. Approximately 105 g
c. Approximately 35 g
12. More Solubility
a. Approximately 80 °C
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
b. Approximately 40 °C
c. Approximately 40 °C
Enthalpy of Solutions
a. Inorganic: AgNO3 (s)  Ag+ (aq) + NO3− (aq)
Thermodynamic: AgNO3 (s) + 22.8 kJ/mol  AgNO3 (aq)
b. The dissolution process is endothermic (absorbs energy), the crystallization process is exothermic
(releases energy)
c. The temperature will go down and feel cool, as the solute dissolves.
d. The rate of crystallization and rate of dissolution will be equal or the same at equilibrium.
e. The rate of dissolution will initially increase, because the process needs to absorb energy to occur, by
heating the solution you are adding energy that the dissolution process can use to dissolve more silver
nitrate.
f. The increased temperature will allow for more silver nitrate solute to be dissolved into solution.
g. As it cools, the rate of crystallization will increase initially and the solubility of the solute will decrease.
At equilibrium, dissolution and crystallization are opposing forces.
The property of solutions that makes concentration calculations possible is the property that in solutions, solute
particles are uniformly (evenly) distributed throughout the solvent.
mol / L (moles of solute per liter of solution)
Molarity vs. Molality
a. Molarity is used when you want to know the number of particles (moles) of solute in a given volume of
solution, as is common in titration reactions.
b. Molality is used when you want to know the relative numbers of solute and solvent particles using
moles and mass, and therefore not be concerned with volume changes due to temperature changes.
NO!! The combined volume of the solute (KI) and the solvent (water) will not become 1 L of solution.
Calculations 1
a. Sodium carbonate solution
1) 106 g from the periodic table Na2CO3
2) 0.167 M Na2CO3
b. 0.953 M NH4Br
Calculations 2
a. Sulfuric acid solution
1) H2SO4
2) H2O
3) 343 g H2SO4
b. 1,140 g Ba(NO3)2
1.14 × 103 g
0.143 mol NaOH
Calculations 4
a. 132.16 g
b. 3.998 M
Calculations 5
a. The first step is find the molar mass of AgNO3 so you can find the moles of solute.
b. 169.88 g
c. 1000 mL
1.0 × 103 mL
Calculations 6
a. 2 𝐻3 𝑃𝑂4 + 3 𝐶𝑎(𝑂𝐻)2 → 𝐶𝑎3 (𝑃𝑂4 )2 + 6 𝐻2 𝑂
b. 698 g Calcium phosphate, and 243 g Water.
33.3 mL
26. 0.0309 M
27. Calculations 8
a. 441 g
b. 126 g
28. Calculations 9
a. 342 g
b. 0.182 m
29. 0.920 kg
30. 20.2 g
31. Calculations 12
a. 142.04 g
b. 0.112 moles
32. Calculations 13
a. 192.14 g
b. 0.000390 M
3.90 × 10−4 M
33. Calculations 14
a. 74.55 g
b. No effect!
c. 52 g
34. Calculations 15
a. 40.00 g
b. 2 𝑁𝑎 (𝑠) + 2 𝐻2 𝑂 (𝑙) → 𝐻2 (𝑔) ↑ + 2 𝑁𝑎𝑂𝐻 (𝑎𝑞)
c. 0.435 M
35. Calculations 16
a. 62.08 g
b. 13 m is the molality of the water!!
70. m is the molality of the ethylene glycol!
36. Calculations 17 & GRAPH!!!
Solute (g)
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
Solute (g)
0
20
40
60
80
100
120
a. Solubility of AgNO3 increases as the temperature of the water increases.
b. Approximately 250 g
c. Approximately 37 °C
d. 100 g of solute at 10 °C would be unsaturated, because the solubility at 10 °C is about 150 g. 325 g of
solute at 35 °C would be saturated, and because the solubility at 35 °C is about 255 g, there would be 70
g of AgNO3 solid in the container, unable to dissolve.
37. Approximately 74.4 g of KNO3 would come out of solution, provided that the mixture doesn’t remain dissolved
as a supersaturated solution.
38. Calculations 19
a. More sulfuric acid solutions!
1) Sulfuric acid: H2SO4
2) Water: H2O
3) 3.000 m
39. Predictions from data!!!
a. DATA TABLE 1:
Sample # Mixture Type
1
Solution
2
Suspension
3
Colloid
4
Colloid
b. DATA TABLE 2:
Sample # Mixture Type
1
Solution
2
Colloid
3
Colloid
4
Suspension
40. Alloys!!
a. Aluminum is an important component of many alloys because of its properties: It is lightweight, it is
strong, it is an excellent conductor, and it resists corrosion very well.
b. Bronze is an alloy of Copper & Tin
c. Brass is an alloy of Copper & Zinc
d. Steel is any alloy of Iron and Carbon, where the carbon content is less than 2.5% of the solution.
e. Cast Iron is an alloy of pure Iron, Carbon, and the compound cementite which is an iron carbide
compound.
41. Carbon Monoxide 
a. 500 ppm is the concentration where harmful effects of CO will occur within 1 hour!
b. 500 ppm is 2.5 times the limit set by OSHA.