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Pertanyaan

Hitunglah pH dari
1. 0,1 M H2S
2. 0,016 M CH3COOH Ka =1.10-5
3. 0,6 M NaOH
4. 2,5M NH4OH Kb = 1.10-5

Tolong di jawab ka.
Terimakasih

2 Jawaban

  • 1). H2S termasuk asam lemah, maka menggunakan rumus :
    [H+] = √ka x M
    = √10-5 x 0,1
    = √10-6
    =10-³
    PH = - log [H+]
    = - log 10-³
    = 3

    2). CH3COOH termasuk asam lemah, maka menggunakan rumus :
    [H+] = √ka x M
    = √10-5 x 0,016
    =√ 16.10-8
    =4.10-⁴
    PH = - log [H+]
    = - log 4.10-⁴
    =4 - log 4

    3). NaOH termasuk basa kuat, maka menggunakan rumus :
    [OH-] = M x valensi basa
    = 0,6 x 1
    = 0,6 = 6.10-¹
    POH = - log [OH-]
    = - log 6.10-¹
    = 1 - log 6
    PH = 14 - POH
    = 14 - ( 1 - Log 6 )
    = 13 + log 6

    4). NH4OH termasuk basa lemah, maka menggunakan rumus :
    [OH-] = √kb x M
    = √10-5 x 2,5
    = √25.10-6
    = 5.10-³
    POH = - log [OH-]
    = - log 5.10-³
    = 3 - log 5
    PH = 14 - POH
    = 14 - (3 - Log 5)
    = 11 + log 5

    Semoga membantu;))
  • 1. pH = - log [H+]
    pH = - log 0,1
    pH = 1

    2. [H+] =[tex] \sqrt{Ka x Ma} [/tex]
    [H+] = [tex] \sqrt{ 10^{-5} x (1,6 x 10^{-1}) } [/tex]
    [H+] = 1,264 x [tex] 10^{-3} [/tex]
    pH = - log [H+]
    pH = - log 1,264 x [tex] 10^{-3} [/tex]
    pH = 3 + log1,264
    pH = 3 + 0,102
    pH = 3,102

    3. pOH = - log [OH-]
    pOH = - log6 x [tex] 10^{-1} [/tex]
    pOH = 1 + log6
    pOH = 1,78
    pH = 14 - pOH
    pH = 14 - 1,78
    pH = 12,22

    4. [OH-] = ??

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