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प्रश्न
Give reasons for the following statement:
Transition metals and most of their compounds show paramagnetic behaviour.
Give reasons:
Transition metals show paramagnetism.
Why do most of the transition metals show paramagnetic behaviour?
Why do most of the transition metals and their compounds exhibit paramagnetic behaviour?
Explain giving reasons:
Transition metals and many of their compounds show paramagnetic behaviour.
Why do most of the transition metals and their compounds exhibit paramagnetic behaviour? How is their paramagnetic behaviour related to the number of unpaired electrons?
Explain the following:
Transition metals and their compounds generally exhibit a paramagnetic behaviour.
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उत्तर
- They have unpaired electrons in their (n − 1)d orbitals.
- The presence of these unpaired electrons causes attraction towards a magnetic field, resulting in paramagnetic behavior.
- The number of unpaired electrons increases from left to the middle of the transition series, so paramagnetism increases and then decreases towards the end.
- Transition metals or ions with all paired electrons show diamagnetism, not paramagnetism.
Thus, paramagnetism in transition metals arises from unpaired electrons in d-orbitals, causing magnetic moments.
Notes
Students can refer to the provided solutions based on their preferred marks.
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संबंधित प्रश्न
How would you account for the following?
Transition metals exhibit variable oxidation states.
Calculate the number of unpaired electrons in the following gaseous ions:
Mn3+, Cr3+, V3+ and Ti3+. Which one of these is the most stable in an aqueous solution?
Following are the transition metal ions of 3d series:
Ti4+, V2+, Mn3+, Cr3+
(Atomic numbers: Ti = 22, V = 23, Mn = 25, Cr = 24)
Answer the following:
1) Which ion is most stable in an aqueous solution and why?
2) Which ion is a strong oxidising agent and why?
3) Which ion is colourless and why?
The paramagnetic character in the 3d-transition series elements increases up to Mn and then decreases.
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
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.
Assertion: The highest oxidation state of osmium is +8.
Reason: Osmium is a 5d-block element.
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
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`]
The E° value for the Mn2+/Mn2+ couple is more positive than that of Cr3+/Cr2+ or Fe3+/Fe2+ due to the change of:
