100ml larutan koh 0,01m dicampurkan ke dalam 100 ml larutan ca(oh)2 0,01m ph campuran larutan tersebut adalah

Diketahui :
V larutan KOH = 100 ml = 0,1 L
Molaritas KOH = 0,01 M
V larutan Ca(OH)2 = 100 ml = 0,1 L
Molaritas Ca(OH)2 = 0,01 M

Ditanya : pH campuran ?

Jawab :

[OH-] KOH :
= b . M
= 1 . 0,01 M
= 10-² M

[OH-] Ca(OH)2 :
= b . M
= 2 . 0,01 M
= 2 × 10-² M

[OH-] Campuran :

:[OH-] KOH. V KOH + [OH-] Ca(OH)2 . V Ca(OH)2
______________________________________
V KOH + V Ca(OH)2

: 10-² M . 0,1 L + 2 × 10-² M . 0,1 L
__________________________________
0,1 L + 0,1 L

: 3 × 10-³ ML
_____________
0,2 L

:1,5 × 10-² M

pOH campuran :
= – log [OH-]
= – log 1,5 × 10-²
= – ( log 1,5 + log 10-²)
= – log 1,5 – log 10-²
= 2 – log 1,5

pH Campuran :
= 14 – pOH
= 14 – ( 2 – log 1,5)
= 14 – 2 + log 1,5
= 12 + log 1,5