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larutan NaOH 80% massa ( Mr = 40 ) memiliki fraksi mol NaOH sebesar ....

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  • NaOH 80% massa
    Mr NaOH = 40
    Mr air = 18

    Fraksi mol NaOH / Xt ... ?

    massa NaOH 80% ==> 80 gram dalam 100 gram larutan
    massa air = 100 - 80 = 20 gram

    mol pelarut / np (pelarutnya air)
    np = gr/Mr
    np = 20/18
    np = 1,11 mol

    mol zat terlarut / nt (mol NaOH)
    nt = gr/Mr
    nt = 80/40
    nt = 2 mol

    Fraksi mol NaOH / Xt
    Xt = nt / (nt + np)
    Xt = 2 / (2 + 1,11)
    Xt = 2 / 3,11
    Xt = 0,64

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