Learning Check pH2 The [OH-] of a solution is 5 x M. What is the [H 3 O + ] of the solution? 1) 2 x M 2) 1 x M 3) 2 x M

Solution pH2 The [OH - ] of a water solution is 5 x M. What is the [H 3 O + ] in the solution? [ H 3 O + ] = 1.0 x x On some calculators: 1.0 EE +/- 14  5 EE +/- 5 = 2 x M

Learning Check pH3 A.The [OH - ] when [H 3 O + ] of 1 x M 1) 1 x M 2) 1 x M 3) 1 x M B.The [H 3 O + ] when [OH - ] of 5 x M 1) 1 x M 2) 2 x M 3) 2 x M

Solution pH3 K w = [H 3 O + ][OH - ] = 1.0 x A. (3) [OH - ] = 1.0 x = 1.0 x x B. (2) [H 3 O + ] = 1.0 x = 2 x x

pH Indicates the acidity [H 3 O + ] of the solution pH = - log [H 3 O + ] From the French pouvoir hydrogene (“hydrogen power” or power of hydrogen)

In the expression for [H 3 O + ] 1 x 10 -exponent the exponent = pH [H 3 O + ] = 1 x 10 -pH M pH

pH Range Neutral [H + ] > [OH - ] [H + ] = [OH - ] [OH - ] > [H + ] Acidic Basic

Some [H 3 O + ] and pH [H 3 O + ] pH 1 x M 5 1 x M 9 1 x M 11

pH of Some Common Acids gastric juice1.0 lemon juice2.3 vinegar2.8 orange juice3.5 coffee5.0 milk6.6

pH of Some Common Bases blood 7.4 tears 7.4 seawater 8.4 milk of magnesia10.6 household ammonia11.0