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TS EAMCET · Chemistry · d and f Block Elements

Which of the following pairs of ions are colourless?

  1. A \(\mathrm{Ti}^{3+}, \mathrm{Cu}^{2+}\)
  2. B \(\mathrm{Sc}^{3+}, \mathrm{Zn}^{2+}\)
  3. C \(\mathrm{Co}^{2+}, \mathrm{Fe}^{3+}\)
  4. D \(\mathrm{Ni}^{2+}, \mathrm{V}^{3+}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(\mathrm{Sc}^{3+}, \mathrm{Zn}^{2+}\)

Step-by-step Solution

Detailed explanation

\[ \mathrm{Sc}^{3+}=[\mathrm{Ar}] 3 d^0, \mathrm{Zn}^{2+}=[\mathrm{Ar}] 3 s^{10} \] Both of these ions have no unpaired electron, hence these are colourless.