Ionic compound lattice structure which is a regular arrangement of ions. And have strong electrostatic force of attraction between them.
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| Strong electrostatic force of attraction |
The strength of these electrostatic forces of attraction depends on the ionic radii of the ions.
The smaller the radius of the ions the closer they are to each other. And so the electrostatic force of attraction increases by increasing the bond of Enthalpy.
Ions with higher charges also have stronger electrostatic force of attraction, resulting in increase bond enthalpy.
Electrolysis of Ionic Compounds:
Ionic compounds can be electrolysed in molten of aqueous state. The positive ions (cation) get attracted towards the negative electron (cathode). And the negative ion (anion) moves towards the positive electron (anode).
If we do the electrolysis of a compound that has coloured ions, the movement of the ions will be will be visible towards the anode and cathode.
In the electrolysis of copper to chromate, the copper ions are blue and the chromate ions are yellow.
We can see that the yellow colour will move towards the anode and the blue color will move towards the cathode. This gives the evidence of ions.
Electron Density Map of Ions:
The electron cloud represents how density the electron are together or how concentrated the electrons are in an atom. When an atom loses an electron, the electron cloud becomes smaller and the ionic radius decreases. When it gains an electron, the electron cloud increases in size as well as the ionic radius.
Trend in ionic radii down the group across the period:
- Down the group the number of shell increases, so the ionic radius increases.
- Across the period, the ionic radius decreases as the effective nuclear charge increase and the ion shrinks inside.
Physical properties of ionic compounds:
1) High Melting and Boiling Point:
Ionic compound have high melting and boiling point due to their lattice structure which consists of a lot of strong electrostatic forces of attraction between oppositely charged ions. To overcome these many electrostatic forces of attraction or ionic bonds, a lot of energy is required.