Principle

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.

Benefits

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

Tasks

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.

Learning objectives

• Solubility
• Dissociation
• Electrolytic conductance
• Activity

Necessary accessories

• Precision balance 620g/0.001g

Software provided. Computer not included.