The solubility of poorly soluble salts is expressed as the solubility product, i.e. the product of the concentration of cations and anions in the solution which are in equilibrium with the solid salt. These concentrations can be determined via conductivity measurements.


  • Good and reproducible results due to temperature control in the experiment.
  • The use of the compact Cobra4 Mobile-Link is space-saving.


  1. Measure the conductivities of saturated aqueous solutions of the salts calcium fluoride and calcium carbonate at 25 °C.
  2. With the aid of tabulated ionic conductivities, calculate the solubility products of the salts from their conductivities.

What you can learn about

  • Solubility
  • Dissociation
  • Electrolytic conductance
  • Activity

Necessary accessories

  • Precision balance 620g/0.001g

Software provided. Computer not included.

Scope of Supply
Device NameItem no.Qty
Erlenmeyer flask, Borosilicate, narrow neck,100ml46141-001,00
Calcium fluoride, powder, puru31175-101,00
Bath for thermostat, makrolon08487-021,00
Hose clip, diam. 8-16 mm, 1 pc.40996-024,00
Wash bottle, plastic, 500 ml33931-001,00
Cobra4 Sensor-Unit Conductivity+12632-001,00
Standard solution 1413µS/cm(25°C), 460ml47070-021,00
Right angle boss-head clamp37697-003,00
Water, distilled 5 l31246-811,00
External circulation set for thermostat Alpha A08493-021,00
Weighing dishes, square shape, 84 x 84 x 24 mm, 25 pcs.45019-251,00
Powder funnel, upper dia. 65mm34472-001,00
Conductivity temperature probe Pt100013701-011,00
Universal clamp37715-003,00
Mortar w. pestle, 70ml, porcelain32603-002,00
Immersion thermostat Alpha A, 230 V08493-931,00
Magnetic stirrer without heating, 3 ltr., 230 V35761-991,00
Calcium carbonate 50030052-501,00
Rubber tubing, i.d. 6 mm39282-003,00
Spoon, special steel33398-001,00
Magnetic stirring bar 30 mm, cylindrical46299-022,00
Retort stand, h = 750 mm37694-002,00
Tubing connector, ID 6-10mm47516-012,00
Downloads and Documents

Document  Filesize
p3030862e.pdfExperiment guide, English188 KB