She’s a 10? Must be on the pH scale cuz she’s pretty basic
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#
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 + ] = M Kw = [H + ] x [OH - ] 1 x = x [OH - ] x = [OH - ] OR: [H + ] = 10 -pH [H + ] = M pH + pOH = 14 pOH = = 6.60 [OH - ] = M
Ex 2: What are [H+] and [OH-] at a pH = 2.3? [H + ] = 10 -pH [H + ] = M Kw = [H + ] x [OH - ] 1 x = x [OH - ] x = [OH - ] OR: [H + ] = 10 -pH [H + ] = M pH + pOH = 14 pOH = 14 – 2.3 = 11.7 [OH - ] = M
Ex 3: What are [H+] and [OH-] at a pH = 5.54? [H + ] = 10 -pH [H + ] = Kw = [H + ] x [OH - ] 1 x = x [OH - ] x = [OH - ] OR: [H + ] = 10 -pH [H + ] = M pH + pOH = 14 pOH = 14 – 5.54 = 8.46 [OH - ] = M