Page 25 - HERA SYAHRIAWATI- ASAM BASA KIMIA SMK X

Contoh :

1. Hitung pH dari :

a. 100 mL larutan KOH 0,1 M !
b. Larutan Ca(OH)2 0,001 M !

Jawab :

+
-
a. KOH → K + OH
-
[OH ] = x. [M(OH)]
-1
= 1 . 0,1 M = 10 M
-1
pOH = - log 10
= 1

pH = 14 – pOH

= 14 – 1

= 13

-
2+
b. Ca(OH)2 → Ca + 2OH
-
[OH ] = x. [M(OH)]
-3
= 2 . 0,001 = 2 x 10 M
-3
pOH = - log 2 x 10
= 3 – log 2

pH = 14 - pOH
= 14 – (3-log 2)

= 11 + log 2

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KIMIA SMK Teknologi dan Rekayasa