Electrolyte solutions - what are they

Electrolyte solutions are solutions which can conduct electricity. Colligative properties such as the lowering of the vapour pressure, depression of the freezing point, elevation of the boiling point and osmotic pressure all depend on the number of individual particles present in solution. They thus give information about the number of particles actually present in solution. For some solutes it is found that the number of particles actually present in solution is greater than would be expected from the formula of the compound. 

In the study of electrolyte solutions, two types of solute can be distinguished  

NaCl(aq) 1 stoichiometric unit — 2 particles CaCl2(aq) 1 stoichiometric unit 3 particles 

X-ray diffraction studies show that some solids consist of discrete molecular units, while others are giant lattices held together by strong electrostatic interactions and with no one cation specifically belonging to any particular aifion, and vice versa. 

The solutes whose structure in the solid is a giant ionic lattice give strongly conducting solutions whose colligative properties place them in category (a). Colours of ionic solutions 

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