Question

Discuss the trends in chemical reactivity of group 15 elements.

Answer 1

General trends in chemical properties of group − 15
(i) Reactivity towards hydrogen:
The elements of group 15 react with hydrogen to form hydrides of type EH₃, where E = N, P, As, Sb, or Bi. The stability of hydrides decreases on moving down from NH₃ to BiH₃.

 (ii)Reactivity towards oxygen:
The elements of group 15 form two types of oxides: E₂O₃ and E₂O₅, where E = N, P, As, Sb, or Bi. The oxide with the element in the higher oxidation state is more acidic than the other. However, the acidic character decreases on moving down a group.
(iii) Reactivity towards halogens:
The group 15 elements react with halogens to form two series of salts: EX3 and EX5.
However, nitrogen does not form NX5 as it lacks the d-orbital. All trihalides (except NX3)
are stable.
(iv) Reactivity towards metals:
The group 15 elements react with metals to form binary compounds in which metals exhibit −3 oxidation states.