Determination of the activity coefficient by a conductivity measurement with CobraSMARTsense Principle The equivalent conductivity of strong electrolytes depends on their concentration. The quotient of the equivalent conductivity at a certain concentration and the equivalent conductivity at infinite dilution is called the conductivity coefficient, which is the result of interionic action. Benefits - Entrance to the world of datalogging by using the Cobra4 Mobile-Link
- Stable and safe construction due to solid stand material
Tasks - Measure the specific conductivities of various potassium chloride and calcium chloride solutions and calculate the equivalent conductivities.
- Determine the equivalent conductivities at infinite dilution using the Kohlrausch equation and calculate the conductivity coefficients.
Learning objectives - Equivalent conductivity
- Ion mobility
- Conductivity
- Interionic action
Necessary accessories - Analytical balance 120g/0.1mg
Cobra SMARTsense - Conductivity, 0...20000 µS/cm, 0...60°C (Bluetooth)
|
12922-01
|
1
|
Standard solution 1413µS/cm(25°C), 460ml
|
47070-02
|
1
|
Protection sleeve for electrode with a diameter of 12 mm
|
37651-15
|
1
|
Retort stand, h = 750 mm
|
37694-00
|
1
|
Right angle boss-head clamp
|
37697-00
|
4
|
Support rod with hole, stainless steel, 10 cm
|
02036-01
|
1
|
Spring balance holder
|
03065-20
|
1
|
Magnetic stirrer without heating, 3 ltr., 230 V
|
35761-99
|
1
|
Magnetic stirring bar 30 mm, cylindrical
|
46299-02
|
1
|
Volumetric flasks, Boro, various sizes
|
36550-00
|
6
|
Volumetric flasks, Boro, various sizes
|
36551-00
|
2
|
Funnels (glass), Boro, various sizes
|
34459-00
|
2
|
Bulb pipettes, various sizes
|
36577-00
|
2
|
Bulb pipettes, various sizes
|
36580-00
|
2
|
Bulb pipettes, various sizes
|
36581-00
|
2
|
Pipettor
|
36592-00
|
1
|
Pipette dish
|
36589-00
|
1
|
Beakers, Boro, high form, various sizes
|
46025-00
|
2
|
Beakers, Boro, high form, various sizes
|
46032-00
|
8
|
Weighing dishes, square shape, 84 x 84 x 24 mm, 500 pcs.
|
45019-50
|
1
|
Spoon, special steel
|
33398-00
|
1
|
Pasteur pipettes, 250 pcs
|
36590-00
|
1
|
Rubber caps, 10 pcs
|
39275-03
|
1
|
Exsicator, DURAN®
|
34130-00
|
1
|
Porcelain plate f.desiccator150mm
|
32474-00
|
1
|
Crystallising dishes, Boro, various sizes
|
46243-00
|
1
|
Wash bottle, plastic, 500 ml
|
33931-00
|
1
|
Silicon grease Molykote, 50 g
|
31863-05
|
1
|
Silica gel, orange, granular, 500 g
|
30224-50
|
1
|
Potassium chloride 250 g
|
30098-25
|
1
|
Calcium chloride, granul. 250 g
|
48021-25
|
1
|
Water, distilled 5 l
|
31246-81
|
1
|
measureLAB, multi-user license
|
14580-61
|
1
| |