Answer the question on basis of passage given below:

Transition metals form a large number of complexes or coordination compounds in which the metal atoms are bound to a number of anions or neutral molecules. The valence bond theory explain the formation, magnetic behaviour and geometrical shapes while the crystal field theory explains the effect of different crystal fields on the degeneracy of d-orbitals energies of the central metal atom/ion. This provides for the quantitative estimation of orbital separation energies, magnetic moments and spectral and stability parameters.

Match List I (Species/ions) with List II (Colour)

Choose the correct answer from the option given below:

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

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

Let us go through each ion and its typical color:

(A) \(Mn^{2+}\) - Manganese(II) ion typically appears pink in aqueous solutions. This color arises due to the presence of water molecules coordinating with the manganese ion, leading to a pink coloration.

(B) \(Fe^{3+}\) - Iron(III) ion exhibits a yellow color in aqueous solutions. This yellow coloration is characteristic of ferric ions and is often observed in solutions containing iron(III) compounds.

(C) \(Ni^{2+}\) - Nickel(II) ion is known for its green coloration. The green color arises due to the electronic transitions within the d-orbitals of the nickel ion, which absorb light in the red region of the spectrum, resulting in the green color observed.

(D) \(Cu^{2+}\) - Copper(II) ion typically appears blue in aqueous solutions. The blue coloration arises due to the electronic transitions within the d-orbitals of the copper ion, which absorb light in the orange region of the spectrum, resulting in the blue color observed.

Now, let's match these ions with their respective colors:

(A) \(Mn^{2+}\) - (IV) Pink

(B) \(Fe^{3+}\) - (I) Yellow

(C) \(Ni^{2+}\) - (II) Green

(D) \(Cu^{2+}\) - (III) Blue

So, the correct matching is indeed: 2. (A)-(IV), (B)-(I), (C)-(II), (D)-(III)

Each ion's color arises from the electronic transitions within their d-orbitals, which absorb certain wavelengths of light and give rise to the observed colors.