(a) Complete the following chemical reaction equations : (i) Fe_((aq))^(2+) + MnO_(4 (aq))^(-) + H_((aq))^(+) to (ii) Cr_(2)O_(7 (aq))^(2-) + I_((aq))^(-) + H_((aq))^(+) to (b) Explain the following observations : (i) Transition elements are known to form many interstitial compounds . (ii) With the same d^(4) d-orbital configuration Cr^(2+) ion is reducing while Mn^(3+) ion is oxidising . (iii) The enthalpies of atomisation of the transition elements are quite high.

(a) Complete the following chemical reaction equations : (i) Fe_((aq)

1.	(a) Complete the following chemical reaction equations : (i) Fe_((aq))^(2+) + MnO_(4 (aq))^(-) + H_((aq))^(+) to (ii) Cr_(2)O_(7 (aq))^(2-) + I_((aq))^(-) + H_((aq))^(+) to (b) Explain the following observations : (i) Transition elements are known to form many interstitial compounds . (ii) With the same d^(4) d-orbital configuration Cr^(2+) ion is reducing while Mn^(3+) ion is oxidising . (iii) The enthalpies of atomisation of the transition elements are quite high.
Answer» Solution :`5Fe_((aq))^(2+) + MnO_(4 (aq))^(-) + 8H_((aq))^(+) to Mn_((aq))^(2+) + 4H_(2)O(l) + 5Fe_((aq))^(3+)` (ii) `Cr_(2)O_(7 (aq))^(2-) + 6I_((aq))^(-) + 14H_((aq))^(+) to 2 Cr_((aq))^(3+) + 7H_(2)O(l) + 3I_(2)(g)` b (i) The transition metals form a larger number of interstitial compounds in which small ATOMS such a hydrogen , carbon , boron and nitrogen occupy the empty spaces (interstitial sites ) in their lattices . (III) DUE to the presence of large number of unpaired electrons in their atom, they form strong interatomic metallic bonds . Hence they have high ENTHALPIES of atomisation .