How do ionic compounds conduct electricity when molten?

Ionic compounds conduct electricity when molten because their ions are free to move and carry electrical charge.

In solid state, ionic compounds are made up of a lattice structure where ions are held together by strong electrostatic forces of attraction. This rigid structure prevents the ions from moving freely, hence they do not conduct electricity. However, when an ionic compound is melted or dissolved in water, the lattice structure breaks down. The heat energy supplied during melting is enough to overcome the strong forces of attraction between the ions. This allows the ions to move freely and independently.

These free ions are charged particles. When an electric current is applied, the positive ions (cations) move towards the negative electrode (cathode), and the negative ions (anions) move towards the positive electrode (anode). This movement of ions constitutes an electric current, hence molten ionic compounds can conduct electricity.

It's important to note that not all ionic compounds will conduct electricity when molten. The ability to conduct electricity depends on the presence of mobile, charged particles. Therefore, if an ionic compound does not dissociate into ions when melted, it will not conduct electricity.

In summary, the ability of molten ionic compounds to conduct electricity is due to the presence and movement of free ions, which carry the electrical charge. This is a fundamental concept in the study of electrochemistry, a branch of chemistry that deals with the relationship between electricity and chemical reactions.