Question

Hitung pH larutan yang terjadi dari campuran berikut!
100 mL HCN 0,1 M + 50 mL NaCN 0,2 M (Ka HCN= 4x10^-5)

Answer 1

N HCN = 100 (0,1) = 10 mmol
n NaCN = 0,2 (50) = 10 mmol
[H+] = Ka (mmol HCN/NaCN)
[H+] = 4 x 10^-5 (10/10)
[H+] = 4x10^-5
pH = -log [H+]
pH = -log 4x10^-5
pH = 5 - log 4
pH = 4,4