Understanding the Matching Task in Chemistry

This question asks us to match entries from List-I, which contain chemical species, concepts, and materials, with their corresponding descriptions or properties from List-II. To solve this, we need to recall information about each item listed.

Let's analyze the provided matches one by one, based on the correct answer key given.

Analyzing Each Match based on the Provided Key

Match (A) - Mn²⁺ with (IV) Highest oxidation states

Manganese (Mn) is a transition metal known for exhibiting a wide range of oxidation states, including +2, +3, +4, +6, and +7. The highest oxidation state for manganese is +7, found in compounds like permanganate (MnO₄^-). While Mn²⁺ is not the highest oxidation state itself, item (IV) refers to "Highest oxidation states". In the context of manganese's chemistry, discussing its range of oxidation states, including the highest, is relevant.

Match (B) - Spin only Magnetic Moment with (III) μ_s = √(n(n + 2)) BM

The spin-only magnetic moment (μ_s) for transition metal ions is calculated based on the number of unpaired electrons (n). The standard formula for this calculation is given by:

\( \mu_s = \sqrt{n(n+2)} \) BM

Here, 'n' is the number of unpaired electrons, and 'BM' stands for Bohr Magneton, the unit of magnetic moment. This formula is directly provided in List-II (III).

Match (C) - MnO₂ with (I) Pyrolusite ore

Manganese dioxide (MnO₂) is a naturally occurring inorganic compound. Its most common mineral form is pyrolusite. Pyrolusite is a primary ore of manganese and is a significant source for obtaining manganese commercially.

Match (D) - Misch metal with (IV) Highest oxidation states

Misch metal is a specific type of alloy. It primarily consists of rare-earth elements, also known as 4f metals, mainly cerium (around 50%) and lanthanum (around 25%), along with smaller amounts of other rare earths and traces of other elements like iron, sulfur, carbon, aluminum, and calcium. It is used in various applications, such as in lighter flints. Item (IV) refers to "Highest oxidation states". Misch metal is an alloy of metals and is not directly related to the concept of highest oxidation states of an individual element, let alone being an example of it. While rare earth elements do exhibit oxidation states (commonly +3), the description in (IV) is general and the match between Misch metal and "Highest oxidation states" is not a chemically accurate primary association.

Summary of the Matches

Based on the provided correct answer, the matches are:

The final correct match, based on the structure of the provided answer is (A) - (IV), (B) - (III), (C) - (I), (D) - (IV).

Revision Table: Key Concepts in Matching Questions

Additional Information: Extending Your Knowledge

Let's delve a bit deeper into some of these concepts to enhance your understanding:

• Manganese Oxidation States: Manganese exhibits oxidation states from +2 (like in MnSO₄) to +7 (like in KMnO₄). Other common states include +3 (e.g., Mn₂O₃) and +4 (e.g., MnO₂). The +7 state is the highest and is a strong oxidizing agent.
• Magnetic Moment Calculation: The spin-only formula √(n(n+2)) BM is a simplification that assumes no contribution from orbital angular momentum. For many first-row transition metal ions, this formula gives a good approximation. To use it, you first need to determine the number of unpaired electrons (n) from the electron configuration of the ion in its specific environment. For example, in Mn²⁺, the electron configuration is [Ar] 3d⁵. In a typical environment, all five d electrons are unpaired, so n=5. The spin-only magnetic moment would be \( \sqrt{5(5+2)} = \sqrt{35} \approx 5.92 \) BM.
• Manganese Ores: Besides pyrolusite (MnO₂), other ores of manganese include Braunite (3Mn₂O₃MnSiO₃), Hausmannite (Mn₃O₄), and Rhodochrosite (MnCO₃).
• Uses of Misch Metal: Misch metal's primary use is in the production of lighter flints, where it is alloyed with iron to make ferrocerium. It is also added to metals like steel and aluminum alloys to improve their properties.