Match List I with List II

Choose the correct answer from the options given below:

A-III, B-IV, C-I, D-II

The correct answer is option 2. A-III, B-IV, C-I, D-II.

The colors of transition metal ions in aqueous solutions are often associated with their electronic configurations and the absorption of light. Here's an explanation for each pair:

A. \(Ni^{2+}\) - III. Green
Nickel ions (\(Ni^{2+}\)) in aqueous solutions often appear green. This color is associated with the electronic transitions that involve the d-orbitals of nickel. The green color is typically observed due to the absorption of light in the red region of the spectrum, leaving the complementary green color to be perceived.

B. \(Cu^{2+}\) - IV. Blue
Copper ions (\(Cu^{2+}\)) in aqueous solutions often exhibit a blue color. This is attributed to the electronic transitions involving the d-orbitals of copper. The absorption of light in the red-orange region leads to the perception of the complementary blue color.

C. \(Mn^{2+}\) - I. Pink
Manganese ions (\(Mn^{2+}\)) in certain compounds can produce a pink color. This color arises from specific electronic transitions in the manganese ions. The absorption of light in certain regions of the spectrum results in the perception of pink.

D. \(Ti^{3+}\) - II. Purple
Titanium ions (\(Ti^{3+}\)) in some compounds can display a purple color. The purple hue is linked to electronic transitions involving the d-orbitals of titanium. The absorption of light in specific regions of the spectrum leads to the appearance of purple.

In summary, the colors of transition metal ions in solution are often a consequence of electronic transitions involving d-orbitals. The specific color observed depends on the nature of these transitions and the energy of absorbed light.