1. She’s a 10? Must be on the pH scale cuz she’s pretty basic

2.  We use logarithms to do this  N = 10 x, then log N = x  [H + ] = 10 -pH [OH - ] = 10 -pOH  [H + ] = invlog(-pH) [OH - ] = invlog(-pOH)  On the calculator press 2 nd log-pH#

3.  Ex 1: What are [H+] and [OH-] in a healthy person’s blood that has a pH = 7.40 at temp 298 K? [H + ] = 10 -pH [H + ] = 10 -7.40 M Kw = [H + ] x [OH - ] 1 x 10 -14 = 10 -7.40 x [OH - ] 10 -7.40 2.51 x 10 -7 = [OH - ] OR: [H + ] = 10 -pH [H + ] = 10 -7.40 M pH + pOH = 14 pOH = 14 - 7.40 = 6.60 [OH - ] = 10 -6.60 M

4.  Ex 2: What are [H+] and [OH-] at a pH = 2.3? [H + ] = 10 -pH [H + ] = 10 -2.3 M Kw = [H + ] x [OH - ] 1 x 10 -14 = 10 -2.3 x [OH - ] 10 -2.3 10 -2.3 2.0 x 10 -12 = [OH - ] OR: [H + ] = 10 -pH [H + ] = 10 -2.3 M pH + pOH = 14 pOH = 14 – 2.3 = 11.7 [OH - ] = 10 -11.7 M

5.  Ex 3: What are [H+] and [OH-] at a pH = 5.54? [H + ] = 10 -pH [H + ] = 10 -5.54 Kw = [H + ] x [OH - ] 1 x 10 -14 = 10 -5.54 x [OH - ] 10 -5.54 10 -5.54 2.88 x 10 -6 = [OH - ] OR: [H + ] = 10 -pH [H + ] = 10 -5.54 M pH + pOH = 14 pOH = 14 – 5.54 = 8.46 [OH - ] = 10 -8.46 M