Jawabanmu

2014-08-13T20:50:03+07:00
Fraksi mol metanol : fraksi mol air
5:5

massa metanol = Mr x n
=32 x 5
=160 gr

massa air = Mr x n
=18 x 5
=90
massa total = 160 + 90 = 250 gr

kadar= massa metanol/massa total  x 100 %
=160/250 x 100%
=64%

semoga membantu  :)