Hitung fraksi mol urea dalam larutan urea yang mengandung 30 gram urea da 81 gram air, jika Mr urea =60 dan Mr air =18?

urea: zat terlarut
air : pelarut.

diket:
massa urea = 30 gr
Mr urea= 60
massa air = 81
Mr urea = 18
dit: Xter (fraksi mol terlarut)
dijawab:


mol urea = massa/mr= 30/60=0.5
mol air = massa/mr=81/18= 4.5

Xter= nt/(np+nt)
Xter= 0.5/(4.5+0.5)
Xter=0.5/5= 0.1