The general trends in chemical properties of the group – 15 are as follows:
(i) Reactivity towards hydrogen:
The elements present in group 15 undergo a reaction with hydrogen to form hydrides of type MH3, where M = N,P, As, Sb, or Bi. On moving down a group, the stability of hydrides decreases from NH3 to BiH3.
(ii)Reactivity towards oxygen:
The elements of group 15 form two different types of oxides:M2O3 and M2O5 where M = N, P, As, Sb, or Bi. The oxide with the element that is in the higher oxidation state has more acidity than the others. However, the trend in acidic character decreases on moving down a group.
(iii) Reactivity towards halogens:
The group 15 elements show reactivity towards halogens to form two series of salts EX3 and EX5. However, nitrogen does not form NX5 as it does not have the d-orbital to accommodate more electrons. All trihalides except NX3 are in a stable state.
(iv) Reactivity towards metals:
The elements of group 15 react with the metals to form binary compounds in which metals show −3 oxidation states.