! "
! "!# $
3 /4*' 52 *6% 789 : 7039 8 7; 39
3 0%, 0 < =*$( 5* 5**=*7039 :
] [
10 ]
[ ] [
10 ]
+
−
H C H H
A ≥ A 3"
M H
OH 14 10 8
]
[
10
]
+
−
− = ≤
100
1 ]
HA 3" B,, $ *'C
=
] [
] [ ] [ ]
[
] ].[
[
− +
− +
=
→
=
A
HA K H HA
A
H
3 /4*' 52 *6% 789 : 7039 8 7; 39 (7039 : 789 7; 39
) 2 ( ] [ ] [
] [ ] [ ]
−
+
−
=
OH H
OH H
C K
a
gd gd
a a
H
] [
10 ]
[ , ]
Trang 2789)57; 39 214J* F ) )5NJ<NO'1** *=*? =*' IE FG
a gd
OH
100
1 ] [
]
a a
a
OH H
C K
] [ ] [ ]
−
− +
+
14
10 ]
[H+ = K a C a+ −
a gd
gd
OH
100
1 ] [H , ] [ 100
1 ]
2
[H+ ] = K C a a
100
1 ] [H , ] [ 100
1 ]
F' F<B C H+ = −K a + K a +K a C a
4 2
]
789%: 70 39
% *'M %789 ]
[
] ].[
− +
=
HA
A H
K a
(4789%: 70 39 ≈ B)Q789 : 7039C
D (789 : 789%A8
N , %, 0 * 2* %,(J
=
MS!C
Trang 3] [
] [
] [ ] [
] ][
[
3
3 3
3
− +
+
−
=
→
=
COO CH
COOH CH
K H COOH
CH
H COO
CH
10 ] [
10 10 78 , 1 ]
−
=
H H
U9 8 703
] [
] ][
[
I
I
H A
K I = − +
()5BVC
] [
] [ ]
[
] [ ]
H
HA K
H
HA K
HA
I
II HA I
HA HA K HA K
H+ = I + II
0 II
0 ,[HA ]
]
[HA I ≈C HA I ≈C HA II
0 0
2
]
[H =K HA I C HA I +K HA II C HA II
I
HA C
II
HA C K
R 2M% I) J$/E I %BLC , ,/*'[H+ ] 2 = [H I+ ] 2 + [H II+ ] 2
< : SM
Trang 46* < * 2* %,(J < HSM
0 3$5A 2 E
EA
E
5
0
0
] [
] ][
[
] [
] ][
[
2 2
2
1
−
− +
− +
=
=
HA
A
H
K
A
H
HA
H
K
a
a
] [
] [ ] [
2
2 2 2
A H K
K a a = + −
→
/4*' 52 *6% 789 8 7 89 : 7; 39 8 7039 8 70 39 BVC
(7 89 )5BVC 789 8 7 09 8 7039 8 70 39 : 7; 39 8 7039 8 70 39
→789 8 7 09 : 7; 39 8 70 39 B C
1
]
3 / '$ ()*0 14 5)6 )7 '$
Trang 5] [
] [ ] [ ]
[
] ][
[
− +
−
+
=
→
=
A
HA K H HA
A
H
/4*' 52 *6% 789 8 7 89 : 7; 39 8 7039
7 89 : E → 7039 : E8 789 7; 39
] [ ] [
] [ ] [ ]
− +
+
−
=
OH H
C
OH H
C
K
H
b
a a
] [
] [ ]
+
−
=
H C
H C
K
H
b
a
a
] [
] [ ]
−
+
=
OH C
OH C
K
H
b
a
a
b
a a
b
a
C pK
pH C
C
K
Trang 6C 0%,$%% !; ;; M B< : LML"C )5?$$%% !; ;; M
L ;; 6
C < ,,21