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37. Ke dalam 100 mL larutan CH3COOH 0,2 M (Ka=1x10-5) ditambahkan 100 mL larutan NaOH 0,2 M sehingga terjadi reaksi:

CH3COOH (aq) + NaOH (aq) → CH3COONa (aq) + NaOH (l)

Tentukan harga pH larutan yang terbentuk! (Kw=10-14)

1 Jawaban

  • mol asetat = 100 x 0.2 = 20 mmol
    mol NaOH = 100 x 0.2 = 20 mmol

    ..CH3COOH + NaOH => CH3COONa + H2O
    m.......20...............20
    r.........-20..............-20................+20.............+20
    s.........-....................-........................20..............20

    G = mol garam/v total = 20/200 = 0.1

    OH- = √kw/ka x G = √10^-14/10^-5 x 0.1
    OH- = 10^-5
    pOH = 5
    pH = 14-5 = 9

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