Page 24 - E-LKS Hidrolisis Garam

Contoh Soal

1. Tentukan pH dari larutan garam NaOCl 3 M (Ka HOCl = 3 x 10 )
-8
Jawab :

+

-
NaOCl(aq) → CH3COO (aq) + Na (aq)
3 M 3 M 3 M
-
-
[OH ] = √ [ ] pOH = − log [OH ]

10 −14 -3
=√ 3 10 −8 3 = - log10

−6
= √10 = 3
= 10 -3 pH = 14-3 = 11
Jadi pH larutan garam NaOCl 3 M adalah 11

2. Tentukan pH larutan 100 mL HNO3 0,2 M yang direaksikan dengan 100

-5
NH4OH 0,2 M (Kb NH4OH = 10 )
Jawab :
n HNO3 = M x V n NH4OH = M x V

= 0,2 x 100 = 0,2 x 100

= 20 mmol = 20 mmol

HNO3(aq) + NH4OH(aq)  NH4NO3(aq) + H2O(l)

m 20 mmol 20 mmol - -
r 20 mmol 20 mmol 20 mmol 20 mmol

s - - 20 mmol 20 mmol

+
+
[H ] = √ [ ] pH = − log [H ]

-5
=√ 10 −14 10 = - log10
−1
10 −5
= √10 −10 = 5
= 10 -5

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