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प्रश्न
How is the variability in oxidation states of transition metals different from that of the non-transition metals? Illustrate with examples.
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उत्तर
In transition metals, the oxidation state changes from +1 to higher states by a gradual change of one. For example, in manganese it is found to be +2, +3, +4, +5, +6, +7. In non-transition metals, the change is selective and generally changes by a difference of 2. For example, the oxidation states of Sn are +2 and +4.
संबंधित प्रश्न
Why do the transition elements have higher enthalpies of atomisation?
Which of the 3d series of the transition metals exhibits the largest number of oxidation states and why?
Explain why Cu+ ion is not stable in aqueous solutions?
How would you account for the following:
Of the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.
How would you account for the following?
Transition metals and their compounds act as catalysts.
Give reasons: Sc3+ is colourless in aqueous solution whereas Ti3+ is coloured.
Transition metals with lowest melting point is ______.
Maximum magnetic moment is shown by ____________.
Maximum oxidation state is shown by ____________.
Read the passage given below and answer the following question:
The transition metals when exposed to oxygen at low and intermediate temperatures form thin, protective oxide films of up to some thousands of Angstroms in thickness. Transition metal oxides lie between the extremes of ionic and covalent binary compounds formed by elements from the left or right side of the periodic table. They range from metallic to semiconducting and deviate by both large and small degrees from stoichiometry. Since electron bonding levels are involved, the cations exist in various valence states and hence give rise to a large number of oxides. The crystal structures are often classified by considering a cubic or hexagonal close-packed lattice of one set of ions with the other set of ions filling the octahedral or tetrahedral interstices. The actual oxide structures, however, generally show departures from such regular arrays due in part to distortions caused by packing of ions of different size and to ligand field effects. These distortions depend not only on the number of d-electrons but also on the valence and the position of the transition metal in a period or group.
In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.
Assertion: Crystal structure of oxides of transition metals often show defects.
Reason: Ligand field effect cause distortions in crystal structures.
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
Assertion: \[\ce{Cu^2+}\] iodide is not known.
Reason: \[\ce{Cu^2+}\] oxidises \[\ce{I^-}\] to iodine.
On the basis of the figure given below, answer the following questions:
- Why Manganese has lower melting point than Chromium?
- Why do transition metals of 3d series have lower melting points as compared to 4d series?
- In the third transition series, identify and name the metal with the highest melting point.
A complex in which dsp2 hybridisation takes place is ______.
Match List - I with List - II.
| List - I | List - II | ||
| (A) | [Fe(CN)6]3− | (i) | 5.92 BM |
| (B) | [Fe(H2O)6]3+ | (ii) | 0 BM |
| (C) | [Fe(CN)6]4− | (iii) | 4.90 BM |
| (D) | [Fe(H2O)6]2+ | (iv) | 1.73 BM |
Choose the correct answer from the options given below.
Give reasons for the following statement:
Transition metals and most of their compounds show paramagnetic behaviour.
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.
Consider the following standard electrode potential values:
\[\ce{Fe^{3+}_{ (aq)} + e^- -> Fe^{2+}_{ (aq)}}\], E0 = +0.77 V
\[\ce{MnO^{-4}_{ (aq)} + 8H^+ + 5e^- -> Mn^{2+}_{ (aq)} + 4H2O_{(l)}}\], E0 = +1.51 V
What is the cell potential for the redox reaction?
Give a reason for the following:
Transition metals possess a great tendency to form complex compounds.
