1. Acid and Bases

2. Common Household Items

3. Properties of Acids Acid solutions conduct electricity well
Acids react with many metals
Sour taste (lemon)
Generate hydronium ions (H3O)
pH is less than 7
Many acids are liquids or gases

4. Properties of Bases Also an electrolyte Many bases are solids
Slippery to touch
Generate hydroxide ions (OH-)
pH of 8 or higher

5. Definition of an Acid
Bronsted-Lowry acid: a substance that donate a proton to another substance
HCl + H2O  H3O + Cl

6. Definition of a base
Bronsted-Lowry base: a substance that accepts a proton
NH3 + H20  NH4 + OH

8. Kw Water can act both as an acid and a base
The self-ionization constant of water is when the products of the concentrations of the two ions that are in equilibrium with water;
[H3O +][OH-]
Kw = 1.00 x
Kw is always a constant. Anything that increases one ion concentration, will decrease the other ion concentration.

9. Meaning of pH
pH is a value used to express the acidity or alkalinity of a solution.
pH below 7 is acidic
pH of 7 is neutral
pH above 7 is basic

10. Calculations pH = - log [H3O+] [H3O+] = 10-pH
Solution of pH = 0 is very acidic!
Solution of pH = 14 is very basic
Refer to p. 543 for calculator help

11. calculations pH = -log [H3O]
Take the logarithium of the [H3O] and change the sign to negative.
[H3O] = 10 –pH
Change the sign of the pH
Use the antilog to raise the 10.

12. Calculations What is the pH of a 0.00010 M of HNO3?
pH = -log (1.0 x 10 -4) = -(-4.00) = 4.00
What is the pH of a M solution of KOH?
You must use Kw.
[H30] = kw = (1.0 x ) = x
[OH] (1.36 x 10 -2)
Then pH = - log (7.35 x ) = 12.13

13. Calculations
What are the hydronium and hydroxide ions in a sample of rain that has a pH of 5.05?
[H3O] = 10 –5.05 = 8.9 x 10-6 M
[OH] = Kw = x 10-14
[H3O] x 10-6
= 1.1 x 10-9 M