Question

Discuss the pattern of variation in the oxidation states of the following:

P to Bi

Answer 1

1. Group 15 elements have valence electrons ns² np³, showing oxidation states from −3 to +5.
2. N and P show −3 state due to high electronegativity and small size.
3. Tendency to form −3 decreases from As to Bi due to increased size and lower electronegativity.
4. +3 and +5 states occur by losing electrons; +3 stability increases and +5 stability decreases down the group due to the inert pair effect.
5. Bi rarely shows +5; heavier elements use vacant d-orbitals to attain the +5 state.
6. Overall, there are −3 state decreases, +3 state stability increases, and +5 state stability decreases from P to Bi.