Properties of ionic compounds
There are properties that are shown by ionic compounds. These are:
- Contains Ion
- Have ions arrange in a fixed pattern called a crystal lattice
- Are crystalline solids
- Conducts electricity when molten or dissolved in water
– Readily dissolve in water
An example of the properties of ionic compounds is sodium chloride. It has a crystal lattice as seen below. It is important to note at this point that this arrangement of atoms is due to electrostatic forces of attraction between the positive and negative charge of the Sodium cation and the Chlorine anion.
The structure of Sodium Chloride is shown below:
The Sodium cations are represented by the light blue spheres, while the Chlorine anions are represented by the darker green spheres.
Each chloride ion is surrounded by six sodium ions and each sodium ion is surrounded by six chloride ions. The ions are arranged so that they are alternated, i.e., a chloride ion is next to a sodium ion and so on. You will never find two chloride ions or two sodium ions situated next to each other as opposites attracts and like charges repel. This arrangement is a fixed pattern called a crystal lattice and for this reason sodium chloride is a crystalline solid.
Sodium Chloride also has a high melting and boiling points because of this rigid crystalline structure and it requires a large amount of heat energy to break these bonds to form a fluid.