larutan NaOH 80% massa ( Mr = 40 ) memiliki fraksi mol NaOH sebesar ....
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kindi2101
Pertanyaan
larutan NaOH 80% massa ( Mr = 40 ) memiliki fraksi mol NaOH sebesar ....
1 Jawaban
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1. Jawaban NLHa
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