Question

Hitung pH dari : a. 0,025 M larutanNaOH . b. Larutan H2SO4 0,005 M . c. Larutan asam cuka CH3COOH 0,01 jika diketahui harga Ka = 10-4

Answer 1

A.) NaOH 0,025 M

[OH^-] = b * Mb
[OH^-] = 1 * 0,025
[OH^-] = 0,025
[OH^-] = 2,5 × 10^-2

pOH = - log [OH^-]
pOH = - log 2,5 × 10^-2
pOH = 2 - log 2,5

pH = 14 - pOH
pH = 14 - (2 - log 2,5)
pH = 14 - 2 + log 2,5
pH = 12 + log 2,5

b.) H2SO4 0,005

[H^+] = a * Ma
[H^+] = 2 * 0,005
[H^+] = 0,01
[H^+] = 10^-2

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

c.) CH3COOH 0,01 M Ka = 10^-4

[H^+] = √ka*Ma
[H^+] = √10^-4 * 0,01
[H^+] = √10^-4 * 10^-2
[H^+] = √10^-6
[H^+] = 10^-3

pH = - log [H^+]
pH = - log 10^-3
pH = 3