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प्रश्न
Use Hund’s rule to derive the electronic configuration of Ce3+ ion and calculate its magnetic moment on the basis of ‘spin-only’ formula.
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उत्तर
The electronic configuration of Ce and Ce3+ ions is as follows:
Ce (Z = 58): 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f1 5s2 5p6 5d1 6s2
or, [Xe] 4f1 5d1 6s2
Ce3+ (Z = 55): [Xe] 4f1
Thus, Ce3+ has only one unpaired electron, i.e., n = 1
∴ μs = `sqrt(n(n + 2))`
= `sqrt(1 xx (1 + 2))`
= `sqrt3`
= 1.732 BM
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संबंधित प्रश्न
ln which pair highest oxidation states of transition metals are found:
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Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?
What are inner transition elements?
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Explain why transition metals and their compounds act as a catalyst.
Maximum magnetic moment 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.
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Reason: Large number of oxides of transition elements are possible.
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| Element | \[\ce{Fe}\] | \[\ce{Co}\] | \[\ce{Ni}\] | \[\ce{Cu}\] |
| Metallic radii/pm | 126 | 125 | 125 | 128 |
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Copper has an exceptionally positive `"E"_("M"^(2+)//"M")^0` value.
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Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.
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- Ti3+
- Cr2+
- Mn2+
- Fe2+
- Sc3+
Choose the most appropriate answer from the options given below:
