Discuss the trends in chemical reactivity of group 15 elements.

Explanation

The groụp 15 elements differ from.one another appreciably in their chèmical reactivity. Dinitrogen .N_2. is inert at room temperature due to the high bodd enthalpy of .N equiv N. bond .941.4. KJ mol ". Reactivity of .N., increases rapidly with rise in temperature. At high temperature, .N., directly combines with some metals to form ionic nitrides and with non metals to form covalent nitrides."P exists in many alfotropic forms -iwbite red and black" phosphoroits. White phosphorous is. less stable and herice more rèactive than othèr solid phases due tó the angular strain in the .P_3^prime. molecule where the angles are only .60^circ.. It readily catčhes fire in air to give dense white fumes, of .P_4 O_ta^2., White P is insoluble in water, but soluble in carbon disulphide and glows in dark chemiluminescenceRed phosphorous is.much less reactive thari white phosphorous. It does not glow in the dark. ,
i Reactivity towards hydrogen - All the elements of group 15 form hydrides, of the type .EH_3. Where .E-N_1 P, As, Sb. or ..Bi.ii .Reactivity towards-oxygen - AH, these elements form two types of oxides .-E, O_3. and. .E_2 O_3/ ^*.
iii Reactivity towards halogen - These elements react to formi twó series of halides - .EX_3. and .EX_s.. Nitrogen does not form pentabalide dué to non-availability of d-orbitals in its valence shell: N.forms only .NF_s. and no .NF_5^-. is formed.
iv Reactivity towards.metals - All-these elements react with metals to form their binary compounds exhibiting .-3. oxidation state. EgCa_3 ~N_2^* Cag_3 P_2 . Na_3 As_24 Zn_2 Sb_2 Mg_3 ~B_r