Which of the following ions are colourless in the aqueous solutions ?A. `La^(3+)` and `Lu^(3+)`B. `Nd^(3+)` and `Pm^(3+)`C. `Ce^(3+)` and `Pt^(3+)`D. `Sm^(3+)` and `Eu^(3+)`

Which of the following ions are colourless in the aqueous solutions ?A

1.	Which of the following ions are colourless in the aqueous solutions ?A. `La^(3+)` and `Lu^(3+)`B. `Nd^(3+)` and `Pm^(3+)`C. `Ce^(3+)` and `Pt^(3+)`D. `Sm^(3+)` and `Eu^(3+)`
Answer» Correct Answer - 1 Most of the trivalent lanthanoid of compounds except that of `La^(3+)` and `Lu^(3+)` are coloured both in the solide state and in the aqueous solution. The colour of these ions can be attributed due to the presence of unpaired `f-`electrons.

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Which of the following ions are colourless in the aqueous solutions ?A. `La^(3+)` and `Lu^(3+)`B. `Nd^(3+)` and `Pm^(3+)`C. `Ce^(3+)` and `Pt^(3+)`D. `Sm^(3+)` and `Eu^(3+)`

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