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प्रश्न
How would you account for the following: Transition metals form complex compounds.
Account for the following:
Transition metals form a large number of complexes.
Account for the following:
Transition metals form large number of complex compounds.
Give reasons for the following:
Transition elements form complex compounds.
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उत्तर १
The transition elements form complexes because they are able to accept pairs of electrons from donor molecules or ions to form dative covalent bonds. This happens because they have vacant orbitals of suitable energy which can accept the non-bonding pairs from the ligands.
उत्तर २
The transition elements form complexes because of the following reasons:
- Comparatively smaller size of their metal ions.
- Their high ionic charges.
- Availability of vacant d-orbitals so that these orbitals can accept lone pairs of electrons donated by the ligands.
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संबंधित प्रश्न
What are interstitial compounds?
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
How would you account for the following : Transition metals form coloured compounds
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: Cations of transition elements occur in various valence states.
Reason: Large number of oxides of transition elements are possible.
Transition elements form binary compounds with halogens. Which of the following elements will form \[\ce{MF3}\] type compounds?
(i) \[\ce{Cr}\]
(ii) \[\ce{Co}\]
(iii) \[\ce{Cu}\]
(iv) \[\ce{Ni}\]
Match the properties given in Column I with the metals given in Column II.
| Column I (Property) | Column II (Metal) | |
| (i) | An element which can show +8 oxidation state | (a) \[\ce{Mn}\] |
| (ii) | 3d block element that can show | (b) \[\ce{Cr}\] |
| upto +7 oxidation state | (c) \[\ce{Os}\] | |
| (iii) | 3d block element with highest melting point | (d) \[\ce{Fe}\] |
Which of the following species has maximum magnetic momentum?
Which of the following transition metal is not coloured?
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
Account for the following:
Zirconium (Zr) and Hafnium (Hf) are difficult to separate.
