Question

no 12 Kimia Kelas 12

Answer 1

Tf° = 178,4°C
Kf = 37,7 °C kg/mol
massa terlarut = 0,94 gr
m kamfor = 25 gr
Tf = 170,8°C
Mr = ...?

∆Tf = Tf° - Tf = 178,4°C - 170,8°C = 7,6°C

i dari zat terlarut anggap saja 1

∆Tf = Kf × m × i
7,6°C = 37,7°C kg/mol × m × 1
m = 0,2016 m

m = (massa ter/Mr) × (1000/m pel)
0,2016 m = (0,94 gr/Mr) × (1000 gr/25 gr)
Mr = 186,5