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प्रश्न
Give reasons for the following:
The transition metals generally form coloured compounds.
Explain giving reason:
The transition metals generally form coloured compounds.
Compounds of transition metals are generally coloured. Give reason.
Why the transition metals generally form coloured compounds?
Explain giving reason:
Transition elements usually form coloured ions.
Why are most of the transition metals and their compounds coloured? Explain.
Explain why transition elements usually form coloured ions
Why are the compounds of transition elements coloured?
Examine the following observation:
Transition elements generally form coloured compounds.
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उत्तर
Most transition metal ions are coloured in solution and solid states. This is due to the partial absorption of visible light. The absorbed light excites the electron from one orbital to another orbital of the same d-subshell. Since the electronic transitions occur in the d-orbitals of metal ions, they are called d-d transitions. These appear coloured due to the d-d transitions that occur in transition metal ions by absorbing visible light.
Notes
Students can refer to the provided solutions based on their preferred marks.
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संबंधित प्रश्न
Which of the following cations are coloured in aqueous solutions and why ?
Sc3+, V3+, Ti4+, Mn2+ (At. Nos. Sc = 21, V = 23, Ti = 22, Mn = 25)
Write the factors which are related to the colour of transition metal ions.
Which one of the following ions is coloured?
How would you account for the following?
Zr (Z = 40) and Hf (Z = 72) have almost identical radii.
Give reasons:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Fe3+/Fe2+.
Why do transition metal ions possess a great tendency to form complexes?
The paramagnetic character in the 3d-transition series elements increases up to Mn and then decreases.
Why is \[\ce{HCl}\] not used to make the medium acidic in oxidation reactions of \[\ce{KMnO4}\] in acidic medium?
Why EΘ values for Mn, Ni and Zn are more negative than expected?
While filling up of electrons in the atomic orbitals, the 4s orbital is filled before the 3d orbital but reverse happens during the ionisation of the atom. Explain why?
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) \[\ce{Fe}\] |
Fill in the blanks by choosing the appropriate word(s) from those given in the brackets:
(activation energy, Threshold energy, increased, lowered, partially, full, d-d transition, Benzoic acid, benzaldehyde)
Only those transition metal ions will be coloured which have ______ filled d-orbitals facilitating ______.
It has been observed that first ionization energy of 5 d series of transition elements are higher than that of 3d and 4d series, explain why?
The spin magnetic moment of cobalt in the compound Hg [Co(SCN)4] is:-
The complex showing a spin-span magnetic moment of 2.82 B.M. is :-
Among the following pairs of ions, the lower oxidation state in aqueous solution is more stable than the other in:-
Which one of the following characters tie of the transition metal is associated with higher catalytic activity?
Which of the following ions will exhibit colour in aqueous solution?
Give reason for the following statement:
Physical and chemical properties of the 4d and 5d series of the transition elements are quite similar to expected.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
