acids lesson 9 ionization of water. the ph scale water ionizes to a small degree. h 2 o (l) ⇄ h...
DESCRIPTION
2.Calculate the [H + ] and [OH - ] in 1.0 M Ba(OH) 2. Ba(OH) 2 Ba 2+ +2OH M1.0 M2.0 M [H + ][OH - ]=1.0x [H + ][2.0]=1.0x [H + ]=5.0x M In a basic solution the [OH - ] is very large and the [H + ] is very small!TRANSCRIPT
AcidsLesson 9
Ionization of Water
The pH Scale Water ionizes to a small degree. H2O(l) ⇄ H+ + OH-
2H2O(l)⇄ H3O+ + OH-
Kw = [H+][OH-] = 1.0 x 10-14 @ 250 C[H+] and [OH-] are inversely related!1. Calculate the [H+] and [OH-] in 1.0 M HCl.
HCl H+ + Cl-
1.0 M 1.0 M 1.0 M
[H+][OH-] = 1.0 x 10-14
[1.0][OH-] = 1.0 x 10-14
[OH-] = 1.0 x 10-14 MNote that in acid solution the [H+] is large and the [OH-] is small.
2. Calculate the [H+] and [OH-] in 1.0 M Ba(OH)2.
Ba(OH)2 Ba2+ + 2OH-
1.0 M 1.0 M 2.0 M
[H+][OH-] = 1.0 x 10-14
[H+][2.0] = 1.0 x 10-14
[H+] = 5.0 x 10-15 M
In a basic solution the [OH-] is very large and the [H+] is very small!
3. Calculate the [H+] and [OH-] in H2O.
The ionization of water.
H2O ⇄ H+ + OH-
x x
[H+][OH-] = 1.0 x 10-14
x2 = 1.0 x 10-14
[OH-] = [H+] = 1.0 x 10-7 M
Note that in pure water that the [H+] and the [OH-] are equal!
4. The pH scale has three important end points. pH 0 Strong Acid 1.0 M HCl 7 Neutral H2O or NaCl
14 Strong Base 1.0 M NaOH
The pH scale
1.0 M HCl H2O 1.0 M NaOH
pH 0 7 14
pH 0 7 14
A B C D E
5. Match each letter with a formula. All are 1 M. NH3
pH 0 7 14
A B C D E
5. Match each letter with a formula. All are 1 M. NH3 weak base D HCl
pH 0 7 14
A B C D E
5. Match each letter with a formula. All are 1 M. NH3 weak base D HCl strong acid A KOH
pH 0 7 14
A B C D E
5. Match each letter with a formula. All are 1 M. NH3 weak base D HCl strong acid A KOH strong base E HF
pH 0 7 14
A B C D E
5. Match each letter with a formula. All are 1 M. NH3 weak base D HCl strong acid A KOH strong base E HF weak acid B H2O
pH 0 7 14
A B C D E
5. Match each letter with a formula. All are 1 M. NH3 weak base D HCl strong acid A KOH strong base E HF weak acid B H2O neutral C
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
We start the pH scaleat 1.0 M HCl strong acid.1.0 is the same as1.0 x 100
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M Substitute in the [H+] and solve for [OH-]
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M Substitute in the [H+] and solve for [OH-][H+][OH-] = 1.0 x 10-14
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M Substitute in the [H+] and solve for [OH-][H+][OH-] = 1.0 x 10-14
[1][OH-] = 1.0 x 10-14
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M Substitute in the [H+] and solve for [OH-][H+][OH-] = 1.0 x 10-14
[1][OH-] = 1.0 x 10-14
[OH-] = 1.0 x 10-14 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M Let's decrease the [H+] by a factor of 10 and solve for [OH-]
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M Let's decrease the [H+] by a 1.0 x 10-1 M 1.0 x 10-13 M another factor of 10 and solve
for [OH-]
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M Note, this is neutral solution!
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M1.0 x 10-9 M 1.0 x 10-5 M1.0 x 10-10 M 1.0 x 10-4 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M1.0 x 10-9 M 1.0 x 10-5 M1.0 x 10-10 M 1.0 x 10-4 M1.0 x 10-11 M 1.0 x 10-3 M1.0 x 10-12 M 1.0 x 10-2 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M1.0 x 10-9 M 1.0 x 10-5 M1.0 x 10-10 M 1.0 x 10-4 M1.0 x 10-11 M 1.0 x 10-3 M1.0 x 10-12 M 1.0 x 10-2 M1.0 x 10-13 M 1.0 x 10-1 M1.0 x 10-14 M 1.0 x 100 M Note this is the other end of the
pH scale where [OH-] = 1.0 M
Notice that the [H+] scale goes from 1.0 M to 1.0 x 10-14 M going from 1.0 M strong acid to 1.0 M strong base.
This means that the [H+] is changing by a factor of:
1.0 = 1.0 x 1014
1.0 x 10-14
There appears to be a need to simplify the scale.
Why not take the power of the hydrogen ion concentration and get a scale from 0 to -14.
We could take the negative of this and get a simple scale from 0 to 14. This is called the pH scale.
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M1.0 x 10-9 M 1.0 x 10-5 M1.0 x 10-10 M 1.0 x 10-4 M1.0 x 10-11 M 1.0 x 10-3 M1.0 x 10-12 M 1.0 x 10-2 M1.0 x 10-13 M 1.0 x 10-1 M1.0 x 10-14 M 1.0 x 100 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M1.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M1.0 x 10-9 M 1.0 x 10-5 M1.0 x 10-10 M 1.0 x 10-4 M1.0 x 10-11 M 1.0 x 10-3 M1.0 x 10-12 M 1.0 x 10-2 M1.0 x 10-13 M 1.0 x 10-1 M1.0 x 10-14 M 1.0 x 100 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M 01.0 x 10-1 M 1.0 x 10-13 M1.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M1.0 x 10-9 M 1.0 x 10-5 M1.0 x 10-10 M 1.0 x 10-4 M1.0 x 10-11 M 1.0 x 10-3 M1.0 x 10-12 M 1.0 x 10-2 M1.0 x 10-13 M 1.0 x 10-1 M1.0 x 10-14 M 1.0 x 100 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M 01.0 x 10-1 M 1.0 x 10-13 M 11.0 x 10-2 M 1.0 x 10-12 M1.0 x 10-3 M 1.0 x 10-11 M1.0 x 10-4 M 1.0 x 10-10 M1.0 x 10-5 M 1.0 x 10-9 M1.0 x 10-6 M 1.0 x 10-8 M
1.0 x 10-7 M 1.0 x 10-7 M
1.0 x 10-8 M 1.0 x 10-6 M1.0 x 10-9 M 1.0 x 10-5 M1.0 x 10-10 M 1.0 x 10-4 M1.0 x 10-11 M 1.0 x 10-3 M1.0 x 10-12 M 1.0 x 10-2 M1.0 x 10-13 M 1.0 x 10-1 M1.0 x 10-14 M 1.0 x 100 M
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M 01.0 x 10-1 M 1.0 x 10-13 M 11.0 x 10-2 M 1.0 x 10-12 M 21.0 x 10-3 M 1.0 x 10-11 M 31.0 x 10-4 M 1.0 x 10-10 M 41.0 x 10-5 M 1.0 x 10-9 M 51.0 x 10-6 M 1.0 x 10-8 M 6
1.0 x 10-7 M 1.0 x 10-7 M 7
1.0 x 10-8 M 1.0 x 10-6 M 81.0 x 10-9 M 1.0 x 10-5 M 91.0 x 10-10 M 1.0 x 10-4 M 101.0 x 10-11 M 1.0 x 10-3 M 111.0 x 10-12 M 1.0 x 10-2 M 121.0 x 10-13 M 1.0 x 10-1 M 131.0 x 10-14 M 1.0 x 100 M 14
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M 0 We can do the same 1.0 x 10-1 M 1.0 x 10-13 M 1 with the pOH1.0 x 10-2 M 1.0 x 10-12 M 21.0 x 10-3 M 1.0 x 10-11 M 31.0 x 10-4 M 1.0 x 10-10 M 41.0 x 10-5 M 1.0 x 10-9 M 51.0 x 10-6 M 1.0 x 10-8 M 6
1.0 x 10-7 M 1.0 x 10-7 M 7
1.0 x 10-8 M 1.0 x 10-6 M 81.0 x 10-9 M 1.0 x 10-5 M 91.0 x 10-10 M 1.0 x 10-4 M 101.0 x 10-11 M 1.0 x 10-3 M 111.0 x 10-12 M 1.0 x 10-2 M 121.0 x 10-13 M 1.0 x 10-1 M 131.0 x 10-14 M 1.0 x 100 M 14
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M 0 14 1.0 x 10-1 M 1.0 x 10-13 M 1 13 1.0 x 10-2 M 1.0 x 10-12 M 2 12 1.0 x 10-3 M 1.0 x 10-11 M 3 11 1.0 x 10-4 M 1.0 x 10-10 M 4 10 1.0 x 10-5 M 1.0 x 10-9 M 5 9 1.0 x 10-6 M 1.0 x 10-8 M 6 8
1.0 x 10-7 M 1.0 x 10-7 M 7 7
1.0 x 10-8 M 1.0 x 10-6 M 8 6 1.0 x 10-9 M 1.0 x 10-5 M 9 5 1.0 x 10-10 M 1.0 x 10-4 M 10 4 1.0 x 10-11 M 1.0 x 10-3 M 11 3 1.0 x 10-12 M 1.0 x 10-2 M 12 21.0 x 10-13 M 1.0 x 10-1 M 13 1 1.0 x 10-14 M 1.0 x 100 M 14 0
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
1.0 x 100 M 1.0 x 10-14 M 0 14 1.0 x 10-1 M 1.0 x 10-13 M 1 13 1.0 x 10-2 M 1.0 x 10-12 M 2 12 1.0 x 10-3 M 1.0 x 10-11 M 3 11 1.0 x 10-4 M 1.0 x 10-10 M 4 10 1.0 x 10-5 M 1.0 x 10-9 M 5 9 1.0 x 10-6 M 1.0 x 10-8 M 6 8 Note that the
pH + pOH = 141.0 x 10-7 M 1.0 x 10-7 M 7 7 @ 250C
1.0 x 10-8 M 1.0 x 10-6 M 8 6 1.0 x 10-9 M 1.0 x 10-5 M 9 5 1.0 x 10-10 M 1.0 x 10-4 M 10 4 1.0 x 10-11 M 1.0 x 10-3 M 11 3 1.0 x 10-12 M 1.0 x 10-2 M 12 21.0 x 10-13 M 1.0 x 10-1 M 13 1 1.0 x 10-14 M 1.0 x 100 M 14 0
pH Scale Kw = [H+][OH-] = 1.0 x 10-14
[H+] [OH-] pH pOH
-11.0 x 100 M 1.0 x 10-14 M 0 14 1.0 x 10-1 M 1.0 x 10-13 M 1 13 1.0 x 10-2 M 1.0 x 10-12 M 2 12 1.0 x 10-3 M 1.0 x 10-11 M 3 11 1.0 x 10-4 M 1.0 x 10-10 M 4 10 1.0 x 10-5 M 1.0 x 10-9 M 5 9 1.0 x 10-6 M 1.0 x 10-8 M 6 8 Note that the
the scale can go1.0 x 10-7 M 1.0 x 10-7 M 7 7 to -1 and 15
1.0 x 10-8 M 1.0 x 10-6 M 8 6 1.0 x 10-9 M 1.0 x 10-5 M 9 5 1.0 x 10-10 M 1.0 x 10-4 M 10 4 1.0 x 10-11 M 1.0 x 10-3 M 11 3 1.0 x 10-12 M 1.0 x 10-2 M 12 21.0 x 10-13 M 1.0 x 10-1 M 13 1 1.0 x 10-14 M 1.0 x 100 M 14 0
15