Transcript II. pH

Ch. 15 & 16 - Acids & Bases
II. pH
(p. 481 - 491)
C. Johannesson
A. Ionization of Water
H 2O + H 2O
Kw =
H3
+
[H3O ][OH ]
C. Johannesson
+
O
+
= 1.0 
OH
-14
10
A. Ionization of Water
 Find
the hydroxide ion concentration of
3.0  10-2 M HCl.
[H3O+][OH-] = 1.0  10-14
[3.0  10-2][OH-] = 1.0  10-14
[OH-] = 3.3  10-13 M
Acidic or basic? Acidic
C. Johannesson
B. pH Scale
14
0
7
INCREASING
ACIDITY
pH =
NEUTRAL
+
-log[H3O ]
pouvoir hydrogène (Fr.)
“hydrogen power”
C. Johannesson
INCREASING
BASICITY
B. pH Scale
pH of Common Substances
C. Johannesson
B. pH Scale
pH =
+
-log[H3O ]
pOH =
-log[OH ]
pH + pOH = 14
C. Johannesson
B. pH Scale
 What
is the pH of 0.050 M HNO3?
pH = -log[H3O+]
pH = -log[0.050]
pH = 1.3
Acidic or basic? Acidic
C. Johannesson
B. pH Scale
 What
is the molarity of HBr in a solution
that has a pOH of 9.6?
pH + pOH = 14
pH = -log[H3O+]
pH + 9.6 = 14
4.4 = -log[H3O+]
pH = 4.4
-4.4 = log[H3O+]
Acidic
[H3O+] = 4.0  10-5 M HBr
C. Johannesson