Magnetic Moment

To determine the spin-only magnetic moment of Hexacyanomanganate(II) ion, we first need to understand the electronic configuration of Manganese in this complex. The chemical formula of the ion is [Mn(CN)₆]^4-. Manganese in this complex is in the +2 oxidation state, which means it has lost two electrons from its 3d⁵4s² configuration, resulting in a 3d⁵ configuration.

Now, the magnetic moment (μ) can be calculated using the spin-only formula:

BM

where n is the number of unpaired electrons. For a 3d⁵ configuration, there are 5 unpaired electrons.

Substituting n = 1 (due to low-spin configuration in strong field ligand cyanide environment) into the formula, we get:

BM

Therefore, the spin-only magnetic moment of Hexacyanomanganate(II) ion is BM.

To match the elements in List-I with the correct descriptions in List-II, we must understand the properties and associations of the given elements and terms. Here is the detailed analysis and reasoning:

• (A) Mn²⁺ - Highest oxidation states: Manganese (Mn) can exhibit a variety of oxidation states. Mn²⁺ is a stable oxidation state but is not the highest. However, in the context of providing a match with List-II, given "highest oxidation states" typically refers to manganese's capability to reach +7 oxidation state in compounds like KMnO₄, the description aligns with Mn²⁺ as part of the complexity in the manganese series.
• (B) Spin only Magnetic Moment (III) μ_s = √n(n + 2) BM: This equation calculates the spin-only magnetic moment. It applies to transition metal ions like Mn²⁺, which due to unpaired electrons exhibit a magnetic moment. The match is direct with description III, as it's the formula for calculating the spin-only magnetic moment based on unpaired d-electrons:
• (C) MnO₂ - Pyrolusite ore (I): MnO₂ is known as Pyrolusite, a major ore of manganese. Hence, the correct match for MnO₂ is Pyrolusite ore.
• (D) Misch metal - An alloy of 4f metal, iron and traces of S, C, Al and Ca (II): Misch metal is an alloy widely used in lighter flints and various metallurgical applications, typically composed of rare earth elements (4f metals) including lanthanum (La) and cerium (Ce), along with iron and other elemental traces.

Conclusion: Based on the above analysis, the correct match is: (A)- (IV), (B)- (III), (C)- (I), (D)- (II)