kimia fisika

1. PHYSICAL CHEMISTRY
PHASE DIAGRAM

2. Phase diagram
2 components
liquid - liquid

5. Experiment : to determine the graphs of
phenol composition-temperature and the critical
solution temperatures
[phenol]
(%)
8 11 20 50 63 70 80
Phenol
(mL)
4 5.5 10 25 31.5 35 40
Water
(mL)
46 44.5 40 25 18.5 15 10
Results :

8. Phase diagram
2 components
liquid - vapor

9. If the interactions between A and
B stabilise the liquid phase then
the vapour pressure will be
depressed below its ideal value
and the boiling temperature
raised.
Many liquid mixtures deviate
from the ideal behaviour
predicted by Raoult's law. Ideal-
dilute solutions are those for
which the solvent obeys Raoult's
law and the solute Henry's law.

10. Ideal
solution

12. In a fractional distillation, the boiling
and condensation cycle is repeated to
get a pure substance. This technique is
used to separate volatile liquids.
The vapor is collected and condensed
in a simple distillation. This technique
is used to separate a volatile liquid
from a non-volatile solute or solid.
Distillation
distillate
condensation

13. azeotrope
Non ideal
solution
Azeotrope:
2 different types:
a high-boiling azeotrope
a low-boiling azeotrope
is a particular
mixture (two or
more miscible
liquids) which
does not change
the composition
during the
distillation
In a high-boiling azeotrope if a maximum occurs in the
phase diagram, the liquid is stabilized due to favorable
interactions between A and B molecules

14. the liquid is destabilized due to
unfavorable interactions between
A and B molecule
a low-boiling
azeotrope

15. Phase diagram
2 components
liquid – liquid &
Liquid - vapor

17. X benz 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
PT 64 78 94 109 122 136 148 158 168 178 186
Problems :
1. Jika sebanyak 10 g A dan 50 g B dicampurkan pada suhu 25C.
Keduanya hanya bercampur sebagian dan membentuk dua fasa.
Jika % berat A dalam fasa I adalah 5%, dan dalam fasa II adalah 60%,
hitung massa A dan B dalam dua fasa yang berada dalam
kesetimbangan
2. Sistem benzena-toluena membentuk campuran dan tekanan total
campuran tersebut merupakan fungsi dari komposisi sebagaimana
yg diperlihatkan dalam tabel berikut.
Buatlah diagram fasa P vs x untuk sistem tersebut !
Apakah sistem tersebut merupakan larutan ideal atau membentuk
azeotrop ?
jika larutan awal memiliki x benzena = 0,4 pada suhu berapa
sebanyak ¾ bagian teruapkan ?