Jawaban:

5+½ log 3

Penjelasan:

Diketahui:

mol HCl = M. vol = 0,1 . 100 ml = 10 mmol

mol Fe(OH)₂ = M .vol =0,1. 50 ml= 5 mmol

persamaan reaksi:

2 HCl + Fe(OH)₂ ⇒ FeCl₂ + 2H₂O

m:10mmol...5mmol

r: -10mmol. -5mmol

s: 0mmol...0mmol.......5mmol

Jadi setelah reaksi terbentuk 5mmol FeCl₂

→ garam hidrolisis parsial asam

Volume = 100mL + 50 mL = 150 mL

M FeCl₂ = 5mmol/150 mL = ⅓ x 10⁻¹

[H⁺] = √[Kw/Kb . M. valensi]

[H⁺] = √[10⁻¹⁴/10⁻⁵. ⅓ x 10⁻¹x1]

[H⁺] = √[10⁻¹⁰x ⅓]

[H⁺] = 3⁻½ x 10⁻⁵

pH = - log[H⁺] = -log (3⁻½ x 10⁻⁵)

pH = 5+½ log 3