Distribution equilibrium  ![]()
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
Principle At constant temperature and under constant pressure, a dissolved
substance distributes itself between two immiscible liquids in a
constant concentration ratio. This ratio is equal to the partition
coefficient (distribution coefficient) of the substance examined in
the given two-phase system. Benefits - Modern, easy-to-use photospectrometer
Tasks - Measure the extinction of various concentrated solutions of
trans-azobenzene in acetonitrile at constant wavelength.
Subsequently determine the equilibrium concentrations (extinctions)
of trans-azobenzene in the system n-heptane /
acetonitrile after single and repeated distribution at constant
temperature.
- Calculate the partition coefficients and effectiveness of the
extractions from the experimental data and compare them.
Learning objectives - Principles of thermodynamics
- Partial molar free enthalpy (chemical potential)
- Equilibrium between phases
- Distribution and extraction
- Nernst distribution equation
- Lambert-Beer law
- Photometry
Necessary accessories - Precision balance 620g/0.001g
Scope of delivery |
Compact – Spectrometer with Fiber Optic Cable
|
35630-00
|
1
| |
Cell for spectrophotometer, optical glass
|
35664-00
|
2
| |
Weighing dishes, square shape, 84 x 84 x 24 mm, 500 pcs.
|
45019-50
|
1
| |
Microspoon, steel
|
33393-00
|
1
| |
Erlenmeyer flasks, Duran®, narrow neck, various sizes
|
36122-00
|
1
| |
Erlenmeyer flasks, Boro, narrow neck, various sizes
|
46143-00
|
1
| |
Erlenmeyer flasks, Boro, narrow neck, various sizes
|
46142-00
|
1
| |
Rubber stoppers, without bore, various diameters
|
39262-00
|
1
| |
Rubber stoppers, without bore, various diameters
|
39259-00
|
2
| |
Volumetric flasks, Boro, various sizes
|
36547-00
|
4
| |
Volumetric flasks, Boro, various sizes
|
36550-00
|
1
| |
Funnels (glass), Boro, various sizes
|
34457-00
|
1
| |
Retort stand, h = 750 mm
|
37694-00
|
1
| |
Support ring, i.d. 70mm,
|
37721-01
|
2
| |
Right angle boss-head clamp
|
37697-00
|
2
| |
Separatory funnel 250 ml pear-sh.
|
36884-00
|
4
| |
Separatory funnel 1000 ml
|
35850-04
|
1
| |
Bulb pipettes, various sizes
|
36578-00
|
1
| |
Bulb pipettes, various sizes
|
36579-00
|
2
| |
Pipette dish
|
36589-00
|
1
| |
Pipettor
|
36592-00
|
1
| |
Beakers, Boro, high form, various sizes
|
46026-00
|
2
| |
Pasteur pipettes, 250 pcs
|
36590-00
|
1
| |
Rubber caps, 10 pcs
|
39275-03
|
1
| |
Thermometer -10...+50 °C
|
38034-00
|
1
| |
Wash bottle, plastic, 500 ml
|
33931-00
|
1
| |
Acetonitrile 1000 ml
|
30000-70
|
1
| |
n-heptane, extra pure 250 ml
|
31366-25
|
1
|
|
Service
