1. Ch. 8 Solutions, Acids, & Bases
I. How Solutions Form
Definitions
Types of Solutions
Dissolving
Rate of Dissolving

2. A. Definitions
Solution – a mixture that has the same composition throughout the mixture; a homogeneous mixture.
Solute - substance being dissolved (in lesser quantity)
Solvent – what the solute is dissolved in (in greater quantity)

3. A. Definitions
Solute - KMnO4
Solvent - H2O

4. Solutions
Solution – a mixture that has the same composition throughout the mix.
Remember the difference between a mixture and a compound.
Compounds have a fixed composition throughout.
Mixtures can have a variable composition throughout.

5. A. Definitions
Solubility – The maximum amount of solute that can be dissolved in the solvent at a given temperature.

6. B. Types of Solutions
Saturated solutions – maximum amount of solute at a given temperature.
Unsaturated solutions – less than the maximum amount of solute at a given temperature.

7. Supersaturated solutions – more than the maximum amount of solute at a given temperature; unstable.

8. B. Types of Solutions concentration UNSATURATED SOLUTION
more solute dissolves
SATURATED SOLUTION
no more solute dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form
concentration

9. C. Dissolving Solvation occurs at the surface of the solute
solvent particles surround solute particles (+/- attraction)
solute particles are pulled into solution

10. D. Rate of Dissolving Solids dissolve faster... more stirring
small particle size (increased surface area)
high temperature

11. Rate of Dissolving Heat it Crush it Stir it
To increase rate of dissolving of SOLIDS:
Heat it
Crush it
Stir it

12. D. Rate of Dissolving Gases dissolve faster... no shaking or stirring
high pressure
low temperature

13. To make a gas dissolve more quickly in a liquid:
Cool it
Increase the pressure of the gas

14. Ch. 8 Solutions, Acids, & Bases
II. Concentration & Solubility

15. A. Concentration % by Volume usually liquid in liquid
Ex: 10% juice = 10mL juice + 90mL water
% by Mass
usually solid in liquid
Ex: 20% NaCl = 20g NaCl + 80g water

16. A. Concentration Concentrated solution large amount of solute
Dilute solution
small amount of solute

17. B. Solubility Solubility
maximum grams of solute that will dissolve in 100 g of solvent at a given temperature
varies with temperature
based on a saturated solution

18. B. Solubility Solids are more soluble at... high temperatures
Gases are more soluble at...
low temperatures
high pressures (Henry’s Law)

19. C. Solubility Charts Reading Solubility Charts
If the number in the problem is EQUAL to the value on the chart the solution is considered SATURATED
If the number in the problem is LESS than the value on the chart the solution is considered UNSATURATED
If the number in the problem is MORE than the value on the chart the solution is considered SUPER SATURATED

20. C. Solubility Charts
Solubility of Compounds in g/100g of Water at various Temperatures
Compound
0◦ C
20◦ C
60◦ C
100◦ C
Ammonium chloride
29.4
37.2
55.3
77.3
Copper(II) sulfate
23.1
32.0
61.8
114
Lead(II)chloride
0.67
1.0
1.94
3.2
Potassium bromide
53.6
65.3
85.5
104
Sodium chlorate
79.6
95.9
137
204

21. Answer Questions on your paper
Chart
How would you classify a solution of 65.3g of potassium bromide at 20ºC? _________
How would you classify a solution of 65.3g of potassium bromide at 60ºC? ____________
How would you classify a solution of 65.3g of potassium bromide at 0ºC? ______________
How would you classify a solution of 37g of ammonium chloride at 20ºC? ___________
How would you classify a solution of 2.5 g of lead (II) chloride at 20ºC? ______________
Saturated
Unsaturated
Supersaturated
Unsaturated
Supersaturated

22. D. Solubility Graphs Solubility Curve
shows the dependence of solubility on temperature

23. Graph
How would you classify a solution of 80g of HCl at 20ºC? ____________
How would you classify a solution of 30g of KNO3 at 20ºC? __________
How would you classify a solution of 39g of NaCl at 100ºC? ________
How would you classify a solution of 80g of NaNO3 at 30ºC? __________
How would you classify a solution of 40g of KClO3 at 80ºC? __________
Supersaturated
Unsaturated
Saturated
Unsaturated
Unsaturated

24. How many grams of solute would you need to form a saturated solution of NH4Cl at 50ºC? _____
How would you classify a solution of 20g of SO2 at 0ºC? ___________
How much KI would you need to form a saturated solution at 10ºC? _____
Which solid decreases in solubility as the temperature increases? _______
50 g
Unsaturated
135 g
Na2SO4

25. Acid, Bases & Salt Video Pre Test Post Test Post Test True False
Neutralization
Base
Anion
Electrolytes
False
True
Post Test
bitter, slippery, high pH
Acids donate hydrogen, Bases accept Hydrogen
An easy way to gauge is something is a strong/weak acid or base

26. Ch. 8 Solutions, Acids, & Bases
III. Particles in Solution
“Like Dissolves Like”
Electrolytes

27. A. “Like Dissolves Like”
Polar substances will only dissolve in polar liquids
Rubbing alcohol and water
Nonpolar substances will only dissolve in nonpolar liquids
Oil and butter
Substances that aren’t the same don’t mix.
Oil and water

28. A. “Like Dissolves Like”
NONPOLAR
POLAR
Detergents
polar “head” with long nonpolar “tail”
can dissolve both types (polar and nonpolar)

29. B. Electrolyte
An electrolyte is a substance that when dissolved in water form ions
Electrolytes get their name from the fact that the conduct electricity in water.
Example: salt dissolved in water
Many sports drinks contain “electrolytes” which are salts dissolved in water

30. B. Electrolytes - + - + - + Electrolyte Weak Electrolyte Non-
salt - +
acetic acid - +
sugar
Electrolyte
Weak
Electrolyte
Non-
Electrolyte
solute exists as
ions only
Easily conducts electricity
solute exists as
ions and
Molecules
Slightly conducts electricity
solute exists as
molecules only
Does NOT conduct electricity

31. B. Electrolytes Dissociation
separation of +/- ions when an ionic compound dissolves in water

32. B. Electrolytes Ionization
breaking apart of polar covalent molecules into ions when dissolving in water

33. Ch. 8 Solutions, Acids, & Bases
IV. Intro to Acids & Bases
Definitions
Properties
Uses

34. HCl + H2O  H3O+ + Cl– A. Acids
Acids contain at least one hydrogen atom that can be removed when the acid is dissolved in water.
These form hydronium ions, H3O+.
Also called a proton donor
HCl + H2O  H3O+ + Cl–

35. A. Bases
Bases form hydroxide ions (OH-) in a water solution.
a proton acceptor
NH3 + H2O  NH4+ + OH-

36. A. Indicators
Indicators are an organic substance that changes color in an acid or base.
Examples:
litmus - red/blue
phenolphthalein - colorless/pink
goldenrod - yellow/red
red cabbage juice - pink/green

37. B. Properties ACIDS BASES bitter taste sour taste pH greater than 7
corrosive
electrolytes
turn litmus blue
slippery feel
sour taste
pH less than 7
corrosive
electrolytes
turn litmus red
react with metals to form H2 gas

38. C. Uses
ACIDS
H3PO4 –phosphoric acid - soft drinks, fertilizer, detergents
H2SO4 – sulfuric acid - fertilizer, car batteries
HCl – hydrochloric acid - gastric juice
HC2H3O2 – acetic acid - vinegar

39. C. Uses BASES NaOH – sodium hydroxide -lye, drain and oven cleaner
Mg(OH)2 – magnesium hydroxide - laxative, antacid
NH3 –ammonia - cleaners, fertilizer

40. Ch. 8 Solutions, Acids, & Bases
V. Strength of Acids & Bases
Strength vs. Concentration
Strong vs. Weak pH

41. A. Strength vs. Concentration
Strong and weak – tells how easy the acid or base dissociates in solution.
Concentration – The amount of acid or base in a solution.
It is possible to have a dilute concentration of a strong acid that would be less harmful than a concentrated weak acid.

42. A. Strength of Acids & Bases
The strength of an acid or base depends on how completely a compound separates into ions when dissolved in water.
Ions can carry an electric charge so a strong acid will carry more electricity than weak acid.

43. B. Strong vs. Weak Strong Acid/Base 100% ions in water
strong electrolyte
HCl, HNO3, NaOH, LiOH - +
Weak Acid/Base
few ions in water
weak electrolyte
HC2H3O2, NH3 - +

44. B. Strong Acids
Acids that ionize almost completely in a solution are strong acids.
Ex: HCl, HNO3, and H2SO4
They have a very low pH (0-1).

45. B. Strong Bases
Bases that dissociate completely in a solution are strong bases.
Ex: NaOH
They have a very high pH (13-14)

46. C. pH Scale a measure of the concentration of H+ ions in a solution
pH (potential of Hydrogen)
a measure of the concentration of H+ ions in a solution
measured with a pH meter or an indicator with a wide color range (0-14) 7
INCREASING
ACIDITY
NEUTRAL
BASICITY 14

47. pH of Common Substances
C. pH Scale
pH of Common Substances

48. ConcepTest
Which of the following "molecular" pictures best represents a concentrated solution of the weak acid HA? A B

49. ConcepTest Is the following statement TRUE or FALSE?
A strong acid has a lower pH than a weak acid.
True-
But: Strong/weak refers to amount of ionization whereas pH refers to concentration of H+.

50. Ch. 8 Solutions, Acids, & Bases
VI. Neutralization
Neutralization Reaction

51. A. Neutralization Reaction
Chemical reaction between an acid and a base.
Products are a salt (ionic compound) and water.

52. A. Neutralization Reaction
ACID + BASE  SALT + WATER
HCl + NaOH  NaCl + H2O =
Neutralization does not always mean pH = 7.

53. A. Neutralization Reaction
KOH + HNO3  H2O + KNO3
Acid
Base
Salt
HNO3
KOH
KNO3