Discuss the general charcteristic of group 15 elements with reference to their configuration, oxidation state, atomic size, ionization enthalpy and electronegativity.
Discuss the general charcteristic of group 15 elements with reference to their configuration, oxidation state, atomic size, ionization enthalpy and electronegativity.
General characteristics of group 15 elements.
(i) Electronic configuration: Valence shell configuration of elements of group 15 is ns2np3. s-orbital ofthese elements is completely filled and p-orbital is half-filled, making their eletronic configuration extra stable.
Nitrogen (7N)=[He]2s22p3Phosphorus (15P)=[Ne]3s23p3Arsenic (33As)=[Ar]3d104s24p3Antimony (51Sb)=[Kr]4d105s25p3Bismuth (83Bi)=[Xe]4f145d106s26p3
(ii) Oxidation states: Common oxidation states exhibited by elements of this group are -3, +3 and +5. The tendency to exhibit -3 oxidation state decreases down the group due to increase in size and metallic character. Bi(last member of the group) hardly forms any compound of -3 oxidation state.
The stability of +5 oxidation state decreases down the group, whereas that of +3 oxidation state increase down the group (due to inert pair effect). N reacts with oxygen showing +1,+2,+3,+4 and +5 oxidations states. P shows +1 and +4 oxidation states in some oxo-acids.
(iii) Atomic size Covalent and ionic raii (in a particular state) increase down the group. From N to P, covalent radius increases considerably. From As to Bi, there is only a small increase in covalent radius. The reason is the presence of completely filled d and (or) f orbitals in heavier members.
(iv) Ionization enthalpy: Ionization enthalpy decrreases down the group due to gradual increase in atomic size. I.E., of group 15 elements is greater than that of group 14 elements and group 16 elements in the corresponding periods. The order of successive ionization enthalpies as expected is
△1H1<△1H2<△1H3.
(v) Electronegativity: The electronegativity value decreases down the group with increasing atomic size.
General characteristics of group 15 elements.
(i) Electronic configuration: Valence shell configuration of elements of group 15 is ns2np3. s-orbital ofthese elements is completely filled and p-orbital is half-filled, making their eletronic configuration extra stable.
Nitrogen (7N)=[He]2s22p3Phosphorus (15P)=[Ne]3s23p3Arsenic (33As)=[Ar]3d104s24p3Antimony (51Sb)=[Kr]4d105s25p3Bismuth (83Bi)=[Xe]4f145d106s26p3
(ii) Oxidation states: Common oxidation states exhibited by elements of this group are -3, +3 and +5. The tendency to exhibit -3 oxidation state decreases down the group due to increase in size and metallic character. Bi(last member of the group) hardly forms any compound of -3 oxidation state.
The stability of +5 oxidation state decreases down the group, whereas that of +3 oxidation state increase down the group (due to inert pair effect). N reacts with oxygen showing +1,+2,+3,+4 and +5 oxidations states. P shows +1 and +4 oxidation states in some oxo-acids.
(iii) Atomic size Covalent and ionic raii (in a particular state) increase down the group. From N to P, covalent radius increases considerably. From As to Bi, there is only a small increase in covalent radius. The reason is the presence of completely filled d and (or) f orbitals in heavier members.
(iv) Ionization enthalpy: Ionization enthalpy decrreases down the group due to gradual increase in atomic size. I.E., of group 15 elements is greater than that of group 14 elements and group 16 elements in the corresponding periods. The order of successive ionization enthalpies as expected is
△1H1<△1H2<△1H3.
(v) Electronegativity: The electronegativity value decreases down the group with increasing atomic size.
