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Questions
Give reasons for the following:
The transition metals generally form coloured compounds.
Explain giving reasons:
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 reasons:
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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Solution
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.
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RELATED QUESTIONS
Why do the transition elements have higher enthalpies of atomisation?
Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
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For M2+/M and M3+/M2+ systems, the E° values for some metals are as follows:
| Cr2+/Cr | −0.9 V |
| Mn2+/Mn | −1.2 V |
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| Cr3/Cr2+ | −0.4 V |
| Mn3+/Mn2+ | +1.5 V |
| Fe3+/Fe2+ | +0.8 V |
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Ionisation enthalpies
