Question

Explain the oxidation states of Group 16 elements.

Answer 1

• Group 16 elements have general electronic configuration, ns² np⁴, 
• They show variable oxidation states, – 2, + 2, + 4 and -6.
• Since all elements have 6 valence electrons, they tend to gain or share 2 electrons to complete an octet, and show common oxidation state – 2.
• Oxygen being highly electronegative, it shows the common oxidation state -2 in oxides (H₂O, MgO). It shows – 1 oxidation state in peroxides (H₂O₂, Na₂O₂) and + 2 oxidation states in OF₂.
• Except oxygen all other elements have vacant dorbitals, hence they show higher oxidation states + 4 and + 6. 

For example,

• The stability of the + 6 oxidation state decreases but the stability of the +4 oxidation state increases down the group due to the inert pair effect. 
• Bonding in +4 and +6 oxidation states is covalent in nature.