kedalam 100 ml larutan HCl 0,2 M ditambahkan 100mL larutan NaOH 0,1 M. setelah bereaksi pH larutan adalah...

100 mL HCl 0,2 M + 100 mL NaOH 0,1 M

pH ... ?

n HCl = M × V
n HCl = 0,2 × 100
n HCl = 20 mmol

n NaOH = M × V
n NaOH = 0,1 × 100
n NaOH = 10 mmol

#Reaksi
....... HCl + NaOH => NaCl + H2O
M : . 20 ...... 10
R : .. 10 ...... 10
____________---
S : .. 10 ...... --- ........... 10 ....... 10

Yang sisa HCl

M = n / V total
M = 10 / (100 + 100)
M = 10 / 200
M = 0,05

[H^+] = a × Ma
[H^+] = 1 × 0,05
[H^+] = 0,05
[H^+] = 5 × 10^-2

pH = - log [H^+]
pH = - log 5 × 10^-2
pH = 2 - log 5