1. Acid and Base Strength

2. Acids
Have a sour taste.

3. Acids
Turn blue litmus red.
Turn methyl orange red.

4. Acids Will react with: Mg + 2HCl  MgCl2 + H2 MgO + 2HCl  MgCl2 + H2O
some metals to produce a salt and H2.
metal oxides to produce a salt and H2O.
metal carbonates to produce a salt, H2O, and CO2.
bases to produce a salt and H2O.
Mg + 2HCl  MgCl2 + H2
MgO + 2HCl  MgCl2 + H2O
MgCO3 + 2HCl  MgCl2 + H2O + CO2
Mg(OH)2 + 2HCl  MgCl2 + 2H2O

5. Acids
Are electrolytes.
Conduct an electric current when dissolved.

6. Bases Have a bitter taste.
Coffee itself is acidic, but it contains an alkaline compound – caffeine – which contributes to its bitter taste.

7. Bases
Feel slimy or slippery to the touch.

8. Bases Turn red litmus blue. Turn methyl orange yellow.
Turn phenolphthalein pink.
Litmus pH scale.

9. Bases React with acids to produce salt and H2O.
HCl + NaOH  NaCl + H2O

10. Bases
Are electrolytes.

11. Review Properties of Acids Properties of Bases Taste sour.
Turn litmus red.
Proton (H+) donors.
Inc. [H3O+] in aqueous solutions.
Properties of Bases
Taste bitter.
Turn litmus blue.
Proton acceptors.
Inc. [OH-] in aqueous solutions.
Review

12. Review pH Scale Traditionally 0 - 14. pH < 7  Acidic solution.
Can have pH < 0 or > 14.
pH < 7  Acidic solution.
pH = 7  Neutral solution.
pH > 7  Basic solution.
Review

13. pH Scale 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Acidic Basic
pH Scale

14. HCl, A Strong Acid

15. HF, A Weak Acid

16. As [H+] Increases, [OH-1] Decreases
1x10-13 M
1x10-12 M
1x10-11 M
1x10-10 M
1x10-9 M
1x10-8 M
1x10-7 M
1x10-6 M
1x10-5 M
1x10-4 M
1x10-3 M
1x10-2 M
1x10-1 M
1x10-13 M
1x10-12 M
1x10-11 M
1x10-10 M
1x10-9 M
1x10-8 M
1x10-7 M
1x10-6 M
1x10-5 M
1x10-4 M
1x10-3 M
1x10-2 M
1x10-1 M
Acid added to neutral solution
Base added to neutral solution
Neutral Solution
[H+]
[OH-1]

17. [H+] and [OH-1] in Water In any aqueous solution:
[H+] [OH-1] = 1x10-14
As [H+] goes up, [OH-1] must decrease.
As [OH-1] goes up, [H+] must decrease.
In other words, adding an acid to water causes the solution to become more acidic and less basic.
Adding a base to water causes the solution to become less acidic and more basic.

18. [H+] and [OH-1] in Water If [H+] = 1x10-3 M, what is [OH-1]?
[H+][OH-1] = 1x10-14
(1x10-3 M)[OH-1] = 1x10-14
[OH-1] = (1x10-14) / (1x10-3)
[OH-1] = 1x10-11 M
If [OH-1] = 1x10-8 M, what is [H+]?
[H+](1x10-8 M) = 1x10-14
[H+] = (1x10-14) / (1x10-8 M)
[H+] = 1x10-6 M

19. pH pH = power of Hydrogen pH = -log10[H+]
negative logarithmic (powers of ten) scale.
pH = -log10[H+]
If [H+] = 1x10-1 M,
pH = -log(1x10-1 M) = 1
If [H+] = 1x10-2 M,
pH = -log(1x10-2 M) = 2
If [H+] = 1x10-3 M,
pH = -log(1x10-3 M) = 3

20. Calculations Involving pH, pOH, [H+], and [OH-] of strong Acids and Bases
pH = -log [H+]
pOH = -log [OH-]
pOH + pH = 14

21. [H3O+1] and [OH-1]
[H3O+1]
[OH-1]

22. pH and pOH What are the pH values of the following solutions?
1x10-1 M H+
pH = -log(1x10-1 M) = 1
1x10-3 M H+
pH = -log(1x10-3 M) = 3
1x10-5 M H+
pH = -log(1x10-5 M) = 5
1x10-1 M OH-1
[H+] = (1x10-14) / (1x10-1 M) = 1x10-13 M
pH = -log(1x10-13 M) = 13