Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?

2

(a)

The \(E^{\ominus}\left(\mathrm{M}^{2+} / \mathrm{M}\right)\) value for copper is positive (+0.34 V). What is possibly the reason for this? (Hint: consider it's high \({ \Delta }_{ a }{ H }^{ o }\) and low \({ \Delta }_{ hyd }{ H }^{ o } \))

2

(a)

Write chemical equations for the reactions involved in the manufacture of potassium permanganate from pyrolusite ore.

2

(a)

What is meant by 'lanthanoids contraction'? State one use each of lanthanoid metals and their oxides.

2

(a)

Describe the steps involved in the preparation of either potassium dichromate from sodium chromate or potassium permanganate from manganese dioxide.

2

(a)

Chemistry of all lanthanoids is so identical. Explain.

2

(a)

How would you account for the following?
(i) Many of the transition elements are known to form interstitial compounds.
(ii) The metallic radii of the third (5d) series of transition metals are virtually the same as those of the corresponding group members of the second \((4d)\) series.
(iii) Lanthanoids from primarily +3, while the actinoids usually have higher oxidation states in their compounds, +4 or even +6 being typical.

2

(a)

Explain the following observations:
(i) Many of the transition elements are known to form interstitial compounds.
(ii) There is a general increase in density from titanium (Z = 22) to copper (Z = 29).
(iii) The members of the actioned series exhibit a larger number of oxidation states than the corresponding members of the lanthanoid series.

2

(a)

Which out of \(Lu(OH_{ 3 })\) and \(La(OH)_{ 3 }\) is more basic and why?

2

(a)

Explain as to why the \(E^{ \Theta }\) value for the \(Mn^{ 3+ }|Mn^{ 2+ }\) couple is much more positive than that for \(Cr^{ 3+ }|Cr^{ 2+ }\) or \(Fe^{ 3+ }|Fe^{ 2+ }\) .

2

(a)

Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with
(i) iron(II) ions
(ii) SO2 and
(iii) oxalic acid?
Write the ionic equations for the reactions.

2

(a)

Atomic radius of Cu is greater than that of Cr but ionic radius of Cr²⁺ is greater than that of Cu²⁺ . Give suitable explanation.

2

(a)

Give reasons for the following : Variations in the radii of transition elements are not as pronounced as those of representative elements.

2

(a)

Explain why mercury (I) ion exists as \({ Hg }_{ 2 }^{ 2+ }\) ion while copper (I) ion exists as Cu⁺ ion.

2

(a)

In what way do the d - block metals differ from alkali and alkaline earth metals ?

2

(a)