pH = 8 + log 1

PEMBAHASAN

Diketahui :

• massa = 0,7 gram.
• volume = 200 ml.
• Kb = 1 x 10-⁵
• Ar H = 1
• Ar N = 14
• Ar O = 16

Ditanyakan :

• pH larutannya?

Jawab :

Pertama, cari Mr-nya :

Mr NH4OH = Ar N + (5 x Ar H) + Ar O

Mr NH4OH = 14 + (5 x 1) + 16

Mr NH4OH = 35 gram/mol

Kedua, cari molaritasnya :

M = m/Mr x 1000/V

M = 0,7/35 x 1000/200

M = 700 / 7000

M = 0,1 molar

Ketiga, cari [OH-] :

[OH-] = √Kb x Molar

[OH-] = √1 x 10-⁵ x 0,1

[OH-] = √1 x 10-⁶

[OH-] = 1 x 10-⁶

Keempat, cari pOH-nya :

pOH = –log [OH-]

pOH = –log 1 x 10-⁶

pOH = 6 – log 1

Kelima, cari pH-nya :

pH = 14 – pOH

pH = 14 – (6 – log 1)

pH = 8 + log 1

Pelajari lebih lanjut

• Menghitung pH asam kuat yomemimo.com/tugas/5891371
• Menghitung pH basa kuat yomemimo.com/tugas/15984558
• Menghitung pH basa lemah - yomemimo.com/tugas/2690965

Detail jawaban

• Kelas : 11 SMA
• Mapel : Kimia
• Bab : 5 - Larutan Asam Basa
• Kode mapel : 7
• Kode Kategorisasi : 11. 7. 5

Kata kunci : mencari pH larutan.