L.p. |
Skad roztworów |
pH |
CH+ |
CHPO42- ____ CH2PO4 - |
CHPO42- log ____ CH2PO4 - |
|
|
Na2HPO4 [cm3] |
KH2PO4 [cm3] |
|
|
|
|
1. |
3 |
27 |
5.74 |
1.81"10-6 |
0.11 |
-0.96 |
2. |
6 |
24 |
6.08 |
8.32"10-7 |
0.25 |
-0.60 |
3. |
9 |
21 |
6.30 |
5.01"10-7 |
0.42 |
-0.37 |
4. |
12 |
18 |
6.50 |
3.16"10-7 |
0.67 |
-0.17 |
5. |
15 |
15 |
6.67 |
2.14"10-7 |
1.00 |
0 |
6. |
18 |
12 |
6.83 |
1.48"10-7 |
1.50 |
0.18 |
7. |
21 |
9 |
7.02 |
9.54"10-8 |
2.34 |
0.37 |
8. |
24 |
6 |
7.25 |
5.62"10-8 |
4.00 |
0.60 |
9. |
27 |
3 |
7.59 |
2.57"10-8 |
9.01 |
0.95 |
Lp |
pH |
C Na+ |
C K+ |
C H2PO4 - |
C HPO4 -2 |
I |
HPO4 -2 |
H2PO4 - |
Log HPO4 -2 H2PO4 - |
X |
1 |
5.74 |
0.0132 |
0.0594 |
0.0594 |
0.0066 |
0.0792 |
0.3572 |
0.7740 |
-0.3350 |
-1.2950 |
2 |
6.08 |
0.0264 |
0.0528 |
0.0528 |
0.0132 |
0.0924 |
0.3352 |
0.7610 |
-0.3560 |
-0.9560 |
3 |
6.30 |
0.0396 |
0.0462 |
0.0462 |
0.0198 |
0.1056 |
0.3167 |
0.7502 |
-0.3745 |
-0.7445 |
4 |
6.50 |
0.0528 |
0.0396 |
0.0396 |
0.0264 |
0.1188 |
0.3007 |
0.7406 |
-0.3914 |
-0.5614 |
5 |
6.67 |
0.0660 |
0.0330 |
0.0330 |
0.0330 |
0.1320 |
0.2867 |
0.7318 |
-0.4070 |
-0.4070 |
6 |
6.83 |
0.0792 |
0.0264 |
0.0264 |
0.0396 |
0.1452 |
0.2743 |
0.7237 |
-0.4213 |
-0.2418 |
7 |
7.02 |
0.0924 |
0.0198 |
0.0198 |
0.0462 |
0.1584 |
0.2632 |
0.7161 |
-0.4347 |
-0.0647 |
8 |
7.25 |
0.1056 |
0.0132 |
0.0132 |
0.0528 |
0.1716 |
0.2533 |
0.7095 |
-0.4473 |
0.1527 |
9 |
7.59 |
0.1188 |
0.0066 |
0.0066 |
0.0594 |
0.1848 |
0.2442 |
0.7030 |
-0.4592 |
0.4908 |
Na podstawie obliczonych wartoci X oraz pH sporzdzono wykres pH = f(X) . Z wykresu odczytano warto pH dla X=0 , która wyniosa ( 7.08 ) .
pH= pKa ! pKa = 7.08
pKa = - log Ka
-log pKa = - 7.08 ! Ka = 10 -7.08 = 10 -7 * 10 -0.08 = 8.31*10 -8