She’s a 10?

Must be on the pH scale cuz she’s pretty basic

We use logarithms to do this N = 10x, then log N = x [H+] = 10-pH [OH-] = 10-pOH

[H+] = invlog(-pH) [OH-] = invlog(-pOH)

On the calculator press 2nd 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+] = 10-7.40 M

Kw = [H+] x [OH-]

1 x 10-14 = 10-7.40 x [OH-]

10-7.40 10-7.40

2.51 x 10 -7 = [OH-]

OR: [H+] = 10-pH

[H+] = 10-7.40 MpH + pOH = 14

pOH = 14 - 7.40 = 6.60[OH-] = 10-6.60 M

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 MpH + pOH = 14

pOH = 14 – 2.3 = 11.7[OH-] = 10-11.7 M

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 MpH + pOH = 14

pOH = 14 – 5.54 = 8.46[OH-] = 10-8.46 M