1. Calculating Concentration

2. Acid-Base Properties of Water
H2O + H2O H3O+ + OH-
acid
conjugate base
base
conjugate acid
autoionization of water
H2O (l) H+ (aq) + OH- (aq)

3. The Ion Product of Water
H2O (l) H+ (aq) + OH- (aq)
Keq = Kw = [H+][OH-]
The ion-product constant (Kw) is the product of the molar concentrations of H+ and OH- ions at a particular temperature.
At 250C
Kw = [H+][OH-] = 1.0 x 10-14

4. Acid-Base Solutions Solution Is [H+] = [OH-] neutral [H+] > [OH-]
acidic
[H+] < [OH-]
basic

5. pH pH = -log [H+] [H+] = 10−pH [OH-] = 10−pOH pH + pOH = 14.00
Solution Is
neutral
acidic
basic
[H+] = 1.0 x 10-7
[H+] > 1.0 x 10-7
[H+] < 1.0 x 10-7
pH = 7
pH < 7
pH > 7
At 250C
[H+] pH

7. Example 1
The concentration of H+ ions in an aqueous solution is ×1 0 −5 M. Calculate the concentration of OH − ions? Is the solution acidic, basic, or neutral?

8. Example 2
Calculate the concentration of OH − ions in a HCl solution whose hydrogen ion concentration is 1.3 M.

9. Example 1
What is the pH, pOH, and hydroxide ion concentration of a solution with a hydrogen ion concentration of 1.0×1 0 −6 M?

10. Example 2
What is the pH, pOH, and hydrogen ion concentration of a solution if the concentration of the hydroxide ions is 9.6×1 0 −4 M?