1. Electrolytes Acids, Bases & Salts

2. An electrolyte is a substance that will conduct electricity, WHEN DISSOLVED IN WATER .
The electrical conductivity of a solution is a measure of its ability to allow an electrical current to flow through it.

3. Covalent substances do not dissociate when they are dissolved in water
Electrolytic dissociation is the separation of a dissolved compound into two ions of opposite charge
Ionic substances dissociate in water because of the polar nature of the water molecules.
E.g. NaCl
Covalent substances do not dissociate when they are dissolved in water
E.g. sugar

4. The Strength of Electrolytes
The strength of an electrolyte is the degree to which it dissociates into ions. The higher the degree of dissociation, the stronger the electrolyte.
NaCl is a strong electrolyte because many ions are formed
Initial Conditions
100 molecules
After
dissolution
100 ions

5. Initial Conditions 100 molecules After dissolution 90 molecules
Acetic acid is a weak electrolyte because few ions are formed
sugar is a non-electrolyte because no ions are formed
Initial Conditions
100 molecules
After dissolution

6. The strength of the electrolyte depends on it’s nature and it’s concentration

7. Types of Electrolytes
An acid is a substance that releases H+ ions in an aqueous solution
Fruit juices, soft drinks, vinegar, and gastric juices are all acids
The have a sour taste
Litmus paper turns red in an acid

8. The formula for an acid usually begins with an “H” (e. g. HCl)
The formula for an acid usually begins with an “H” (e.g. HCl). Acetic acid (CH3COOH) is an exception because it ends in “H”
An acid is a substance that releases H+ ions in an aqueous solution
An aqueous solution is a solution that contains water.
HCl  H+ + Cl- HS
HNO3
HCl HF
H2SO4

9. Exceptions!!!
C3H8
CH3
C8H18
CH4
C & H only –
are NOT acids!!!

10. (misleading solutions)
Examples
ACIDS
EXCEPTIONS
(misleading solutions)
HNO3
H3PO4
HCl
CH3
CH4
C3H8
NOTE: any “H” combined with carbon by itself is usually an exception and not considered an acid
(called hydrocarbons)

11. A base is a substance that releases OH- ions in an aqueous solution.
Most cleaners (soaps and detergents) are bases
They have a bitter taste
Red litmus paper turns blue

12. The formula for a base usually ends with an “OH” (e. g. NaOH)
The formula for a base usually ends with an “OH” (e.g. NaOH). Ammonia (NH3) is an exception)
Example: NaOH  Na+ + OH-
KOH
LiOH
NaOH
Mg(OH)2
NH3

13. Exceptions!!! C2H5OH CH3OH C2H4(OH)2 Alcohols – are NOT bases!!!
**When OH is found at the end of the formula but attached to a carbon and hydrogen it is an alcohol
Alcohols –
are NOT bases!!!

14. (misleading solutions)
Examples
BASES
EXCEPTIONS
(misleading solutions)
NaOH
LiOH
Mg(OH)2
C2H5OH
CH3OH
CH3COOH
NOTE: any “OH” combined with a carbon and a hydrogen
together is an alcohol

15. INDICATORS Litmus paper is a type of indicator
(USED TO DETECT ACIDS OR BASES)
Litmus paper is a type of indicator
(thin strip of paper that is dipped into a solution)
2 Types: Blue Litmus Paper
Red Litmus Paper
ACIDS – Turn blue litmus paper red
BASES – Turn red litmus paper blue BB

16. Salts are neutral and have no effect on litmus paper
A salt is a substance produced by the chemical bonding of a metallic ion and a nonmetallic ion (other than H+ and OH-). The ions may be polyatomic.
Salts enhance the flavour of food. The best known salt is table salt (NaCl)
They are often used to change the physical properties of various solutions by lowering the freezing points or raising the boiling points
Salts are neutral and have no effect on litmus paper
Ions formed by the dissociation of salts play and important role in the metabolism of living organisms

17. Covalently Bonded Compounds
CCl4
PCl3
CF4
CO2
2 non-metals
are NOT salts!!!

18. (misleading solutions)
Examples
SALTS
EXCEPTIONS
(misleading solutions)
MgCl2
NH4Cl KI
PCl3
CCl4
NOTE: these exceptions just have to be memorized

19. TESTERS: Where do you think these solutions belong?
ACIDS
BASES
SALTS
TESTERS: Where do you think these solutions belong?
1. H3PO4
4. HI
2. C8H18
5. MgCl2
3. Ca(OH)2
6. KOH

20. Summary: Properties of Acids, Bases and Salts

21. SUMMARY: Remember!!
Electrolytic solutions- conduct electricity (acids, bases and salts)
They have free ions in aqueous solution
Also remember: tap water is electrolytic (free ions!...think of “hard water”) versus distilled water (no free ions)
Non-electrolytic solutions – do not conduct electricity (100% pure distilled water, pure alcohols, 2 non-metal compounds)