Question

How is the variability of oxidation states of the transition elements different from that of the non-transition elements? Illustrate with examples.

Answer 1

i. The variability in oxidation states of transition metals is due to the incomplete filling of d-orbitals in such a way that their oxidation states differ from each other by unity.
eg. Fe²⁺ and Fe³⁺, Cu⁺ and Cu²⁺, etc.
ii. In case of non-transition elements, the oxidation states differ by units of two.
eg. Pb²⁺ and Pb⁴⁺, Sn²⁺ and Sn⁴⁺, etc.
iii. In transition elements, the higher oxidation states are more stable for heavier elements in a group.
eg. In group 6, Mo (VI) and W (VI) are more stable than Cr (VI).
iv. In p-block elements, the lower oxidation states are more stable for heavier members due to inert pair effect.
eg. In group 14, Pb (II) is more stable than Pb (IV).