How and you account for the following :
(i) Cabalt (II) is stable in aqueous solution but in the presence of complexing reagents it is easily oxidised.
(ii) The transition elements exhibit high enthalpy of atomization.
(iii) of the `d^4` species, `Cr^(2+)` is strongly reducing while Mn (III) is strongly oxidsing .

Account for the following statements : (i) Co (ii) is stable in aqueous solution but in the presence of strong ligands and air it can get oxidised to Co (III) (at. No Co=27) (ii) of the d^4 species Cr (II) is strongly reducing but Mn (III) is strongly oxidising (at. no Cr= 24 , Mn = 25, Co = 27)

How would you account for the following : (i) Out of the d^(4) species, Cr^(2+) is strongly reducing while manganese (III) is strongly oxidising. (ii) Cobalt (II) is stable in aqueous solution but in the presence of complexing reagents it is easily oxidized. (iii) The d^(1) configuration is very unstable in ions.

How would you account for the following: A) Of the d^(4) species Cr^(2+) is strongly reducing while manganese(III) is strongly oxidizing. B) Cobalt(II) is stable in aqueous solution but in the presence of complexing reagents it is easily oxidized. C) The D^(1) configuration is very unstable in ions.

Account for the following (i) Co(II) is stable in aqueous solution but in the presence of strong ligand and air , it can get oxidized to Co(III) . (ii) [Ni(CN)_(4)]^(2-) is square planar and diamagnetic whereas [NiCl_(4)]^(2-) is tetrahedral and paramagnetic .

How would you account for the following : (i) Cr^(2+) is reducing in nature while with the same d-orbital configuration (d^(4)),Mn^(2+) is oxidising in nature. (ii) In the transition series of metals, the metal which exhibits the greatest number of oxidation states occurs in the middle of the series.

(a) Account for the following : (i) Cu^(+) is unstable in an aqueous solution. (ii) Transition metals form complex compounds. (b) Complete the following equation: Cr_(2)O_(7)^(2-)+8H^(+)+3NO_(2)^(-)rarr

Assign reasons for the following : (i) Cu(I) ion is not known to exist in aqueous solutions. (ii) Transition metals are much harder than the alkali metals. (iii) From element to element, actinoid contraction is greater than the lanthanoid contraction.

Give reasons for the following: (i) Transition metals exhibit a wide range of oxidation states. (ii) Cobalt (II) is very stable in aqueous solutions but gets easily oxidised in the presence of strong ligands. (iii) Actinoids exhibit a greater range of oxidation states than lanthanoids.

How would you account for the following ? (i) With the same d-orbital configuration (d^(4)) Cr^(2+) is reducting agent while Mn^(3+) is an oxidizing agent. (ii) The actionoids exhibits a larger numbe of oxidation states than the corresponding members in the lanthanoid series. (iii) Most of the transition metal ions exhibit characteristic in colours in aqueous solutions.

How would you account for the following ? (i) With the same d-orbital configuration (d^(4)) Cr^(2+) is reducting agent while Mn^(3+) is an oxidizing agent. (ii) The actionoids exhibits a larger numbe of oxidation states than the corresponding members in the lanthanoid series. (iii) Most of the transition metal ions exhibit characteristic in colours in aqueous solutions.