What is Inert Pair Effect? Explain With an Example

Inert pair effect is the occurrence of oxidation states which is two units less than the oxidation group states. The examples of inert pair effect is aluminium which exhibits +3 oxidation state.

Inert Pair Effect

• The inert pair effect is sometimes blamed for the development of oxidation states that are two units less intense than the group oxidation states.
• The resistance of “s” electrons to participate in bonding is known as the “inert pair effect.”

The inert-pair effect is the empirical finding that the heavier elements in groups 13–17 frequently have lower oxidation states than the maximum anticipated for that group, which is typically lower by 2. For instance, although though group 13 elements typically have an +3 oxidation state, the heaviest member of the group, thallium (Tl), is likely to form compounds with an oxidation state of +1.

The 5s2 5s2 and 6s2 6s2 pairs that follow the second and third rows of transition metals, in particular, are less reactive than would be predicted based on periodic patterns such as effective nuclear charge, atomic sizes, and ionisation energies, according to the inert pair effect. Additionally, Sn, Tl, Pb, Sb, and Po do not always exhibit their projected maximum oxidation states, to some extent. Instead, they occasionally create compounds in which their oxidation states are 2 lower than what is normal.