OXIDES & OXOANIONS OF TRANSITION METAL

A Feo is basic in character. R: Oxides of Transition metals are basic when metal is in lower oxidation state

(i) Which transition element in 3d series has positive E_(M^(2+//)M)^(@) value and why ? (ii) Name a member of lanthanoid series which is well known to exhibit to exhibit +4 oxidation state and why? (b) Account for the following : (i) The highest oxidation state is exhibited in oxoanions of transition metals. (ii) HCl is not used to acidify KMnO_(4) solution. (iii) Transition metals have high enthalpy of atomisation.

Transition metals show zero oxidation state with ligands like CO. Explain.

Statement-1: the highest oxidation state of transition metal is exhibited in its oxide or fluoride only. Statement-2: Small size and high electronegativity of O and F can oxidise the metal to its highest oxidation state.

Assertion: MnO is basic whereas Mn_2O_7 is acidic. Reason: Higher the oxidation state of a transition metal in its oxide, greater is the acidic character.

What is meant by 'disproportionation'? Give an example of disproportionation reaction in aqueous solution. OR Suggest reasons for the following features of transition metal chemistry: (i) The transition metals and their compounds are usually paragmagnetic. (ii) The transition metals exhibit variable oxidation states.

Select the correct statement(s) with respect to oxides and oxoanions of transition metals