1. Solutions, Acids, & Bases
III. Particles in Solution
“Like Dissolves Like”
Electrolytes

2. 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

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

4. 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

5. 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

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

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

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

9. 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–

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

11. 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

12. 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 hydrogen (H2) gas

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

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

15. Solutions, Acids, & Bases
V. Strength of Acids & Bases
Strength vs. Concentration
Strong vs. Weak pH

16. 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.

17. 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.

18. 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 - +

19. 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).

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

21. 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

22. pH of Common Substances
C. pH Scale
pH of Common Substances

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

24. 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+.

25. Solutions, Acids, & Bases
VI. Neutralization
Neutralization Reaction

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

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

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