Match List - I with List - II.

Choose the correct answer from the options given below :

List - I contains four familiar salts of the d-block elements and List - II lists the characteristic colours shown by those salts.

Case A (Compound : $$\text{KMnO}_4$$)
The manganate(VII) ion $$\text{MnO}_4^-$$ has an $$n \rightarrow \pi^{*}$$ charge-transfer transition whose absorption lies in the green region of the spectrum; the transmitted (complementary) colour is therefore purple. Hence,
$$\text{KMnO}_4$$  →  Purple colour  (Entry III).

Case B (Compound : $$\text{K}_2\text{Cr}_2\text{O}_7$$)
The dichromate ion $$\text{Cr}_2\text{O}_7^{2-}$$ shows ligand-to-metal charge-transfer bands that make the solution absorb mainly in the violet-blue region; the observed colour is orange. Hence,
$$\text{K}_2\text{Cr}_2\text{O}_7$$  →  Orange colour  (Entry I).

Case C (Compound : $$\text{FeSO}_4\cdot7\text{H}_2\text{O}$$)
In ferrous sulphate the ion present is the high-spin octahedral $$\text{Fe}^{2+}$$ (d6). A weak d-d transition in the red part of the spectrum makes the crystalline salt appear light (pale) green. Hence,
$$\text{FeSO}_4\cdot7\text{H}_2\text{O}$$  →  Light green colour  (Entry IV).

Case D (Compound : $$\text{CuSO}_4\cdot5\text{H}_2\text{O}$$)
Aqueous copper(II) ion, present as $$[\text{Cu(H}_2\text{O})_6]^{2+}$$, undergoes an octahedral d-d transition that absorbs in the orange-red region, imparting an intense blue colour to the salt. Hence,
$$\text{CuSO}_4\cdot5\text{H}_2\text{O}$$  →  Blue colour  (Entry II).

Therefore the required matching is:
(A) − (III),  (B) − (I),  (C) − (IV),  (D) − (II)

Option A which is: (A) − (III), (B) − (I), (C) − (IV), (D) − (II)