Page 73 - MODUL - paling baru - Copy_Neat

e-modul KIMIA 2022

6. B. 4 + log 5
Pembahasan:

[H ] = Ka x
+

0,3
[H ] = 10 x
+
-5
0,15
-5
+
[H ] = 2 x 10
pH = -log [H ]
+
pH = - log 2 x 10
-5
= 5 – log 2
= 5 – (1-log5)
= 4 + log 5

7. A. 5 – log 45
Pembahasan:

KOH + HNO2  KNO2
m = 10 mmol 20 mmol -
r = -10 mmol -10 mmol +10 mmol
s = - 10 mmol 10 mmol

[H ] = Ka x
+

10
[H ] = 4,5 x 10 x
-4
+
10
[H ] = 4,5 x 10 = 45 x 10
-4
+
-5
pH = - log [H ]
+
= - log 45 x 10 -5
= 5 – log 45

8. A. 0,005 M
Pembahasan:
pH = 3 + log 2,5
= 3 + (1 – log 4)
= 4 – log 4
+
[H ] = 4 x 10
-4

[H ] = Ka x
+

V asam = V garam = V

,

4 x 10 = 2 x 10 x [ ]
-4
-4
2

2 10 0,02
[garam] =
2 4 10
[garam] = 0,005 M
e-modul Kesetimbangan Ion dan pH Larutan Penyangga Halaman 60