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Pertanyaan

Berapakah pH dari 50 mL CH3COOH 0,2 M dengan 50 mL NaOH 0,1 M (ka CH3COOH = 2 x 10-5)

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  • Dik : [CH3COOH]= 0,2 M
    V CH3COOH=50 mL=5×10^-2 L=0,05 L
    [NaOH]= 0,1 M
    V NaOH= 50 mL=5×10^-2 L=0,05 L
    Dit : pH....?
    Peny : mencari Mol
    n CH3COOH=[CH3COOH].V CH3COOH
    =(0,2) (5×10^-2)
    =(2×10^-1) (5×10^-2)
    =10×10^-3
    =1×10^-2 mol
    n NaOH=[NaOH].V NaOH
    =(0,1) (5×10^-2)
    =(10^-1) (5×10^-2)
    =5×10^-3 mol
    CH3COOH+NaOH—>CH3COONA+H2O
    mula" :10×10^-5 5×10^-5 — —
    brx :5×10^-5 5×10^-5 5×10^-5 5×10^-5
    sisa. :5×10^-5 — 5×10^-5 5×10^-5

    [H+]=Ka×mol asam/mol garam
    =2×10^-5 (5×10^-5/5×10^-5)coret smua krna sdah habis,sisa
    =2×10^-5
    pH= –log [H+]
    = – log 2×10^-5
    = –(log 2+log 10^-5)
    = –(log 2+(-5)(1))
    = –(log 2 – 5?
    = – log 2+5
    = 5–log 2
    = 5–0,3
    = 4,7

    maaf yach klau salah

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