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प्रश्न
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Oxidation states
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उत्तर
The first series of transition metals (3d series) stable forms lower oxidation states like +2 and +3, and its highest states are strongly oxidizing. Conversely, down the respective vertical columns, the second (4d) and third (5d) series show an increasing stability in their higher oxidation states (such as +6 and +8), making their lower oxidation states relatively uncommon and unstable.
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संबंधित प्रश्न
ln which pair highest oxidation states of transition metals are found:
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?
To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
What are alloys?
Write the factors which are related to the colour of transition metal ions.
How is potassium dichromate prepared from chrome iron ore?
Give reasons for the following:
The transition metals generally form coloured compounds.
Maximum oxidation state is shown by ____________.
Out of \[\ce{Cu2Cl2}\] and \[\ce{CuCl2}\], which is more stable and why?
EΘ of Cu is + 0.34V while that of Zn is – 0.76V. Explain.
Reactivity of transition elements decreases almost regularly from Sc to Cu. Explain.
Match the properties given in Column I with the metals given in Column II.
| Column I (Property) | Column II (Metal) | |
| (i) | Element with highest second ionisation enthalpy |
(a) \[\ce{Co}\] |
| (ii) | Element with highest third ionisation enthalpy |
(b) \[\ce{Cr}\] |
| (iii) | \[\ce{M}\] in \[\ce{M(CO)6}\] is | (c) \[\ce{Cu}\] |
| (iv) | Element with highest heat of atomisation |
(d) \[\ce{Zn}\] |
| (e) \[\ce{Ni}\] |
When a chromite ore (A) is fused with sodium carbonate in free excess of air and the product is dissolved in water, a yellow solution of compound (B) is obtained. After treatment of this yellow solution with sulphuric acid, compound (C) can be crystallised from the solution. When compound (C) is treated with KCl, orange crystals of compound (D) crystallise out. Identify A to D and also explain the reactions.
Which of the following statements is not correct?
Which of the following maxm magnetic moment?
In the ground state of atomic Fe (Z = 26), the spin-only magnetic moment is ______ × 10-1 BM.
(Round off to the nearest integer).
[Given: `sqrt3 = 1.73, sqrt2 = 1.41`]
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
