hitunglah molalitas dan fraksi mol larutan NaOH dalam air yg kadar nya 40% (Mr NaOH =40).
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Pertanyaan
hitunglah molalitas dan fraksi mol larutan NaOH dalam air yg kadar nya 40% (Mr NaOH =40).
1 Jawaban
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1. Jawaban alhafizhwira
NaOH 40% dalam 100 gram larutan = 40 gram
Massa air = 100 - 40 = 60 gram
Molalitas = n . 1000/p
= 40/40 gr/mol . 1000/60
= 16,67 molal
XNaOH = nNaOH / (nNaOH + n air)
= (40/40) / ((40/40) + (60/18))
= 1/(1+3,34)
= 1/4,34
= 0,23