Which of the following cations are coloured in aqueous solution and wh – InterviewSolution

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1.	Which of the following cations are coloured in aqueous solution and why ? `Sc^(3+), V^(3+), Te^(4+), Mn^(2+)` ( At.Nos. `Sc= 21, V = 23, Ti= 22, Mn =25)`
Answer» `Sc^(3+)= 3d^(0)4s^(0)`( No unpaired electron), `V^(3+)= 3d^(2) 4s^(0) `( 2 unpaired electrons).Thus, only `V^(3+)` and `Mn^(2+)` are coloured because they have unpaired electrons.

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