Animated Solution for Chemistry - Metallurgy: Match the anionic species given in Column-I that are present in the ore(s) given in Column-II

Metallurgy often feels like a memory game, but it is deeply rooted in the chemical realities of how elements exist in nature. In this problem, we are tasked with matching a list of common anionic species—Carbonate, Sulphide, Hydroxide, and Oxide—with a set of well-known ores: Siderite, Malachite, Bauxite, Calamine, and Argentite.

The key to unlocking this matrix match is not just rote memorization, but understanding the chemical composition of these naturally occurring minerals. Let's break down the formulas of each ore to reveal their hidden anions.

Before we start matching, we must write down the exact chemical formula for each ore in Column II.

Siderite is an iron ore, specifically iron(II) carbonate, with the formula ${\text{FeCO}}_3$.

Malachite is a beautiful green copper ore. It is a basic copper carbonate, meaning it contains both carbonate and hydroxide ions. Its formula is ${\text{CuCO}}_3\cdot {\text{Cu(OH)}}_2$.

Bauxite is the primary ore of aluminium. While often simplified as hydrated alumina ${\text{Al}}_2{\text{O}}_3\cdot 2{\text{H}}_2\text{O}$, it is actually a mixture of minerals. A more accurate general formula is ${\text{AlO}}_x{\text{(OH)}}_{3-2x}$ (where $0<x<1$), indicating the presence of both oxide and hydroxide species.

Calamine is a zinc ore, specifically zinc carbonate, with the formula ${\text{ZnCO}}_3$.

Argentite is a silver ore, specifically silver sulphide, with the formula ${\text{Ag}}_2\text{S}$.

Now, let's look for the Carbonate (${\text{CO}}_3^{2-}$) anion. Scanning our list of formulas, we see that Siderite (${\text{FeCO}}_3$), Malachite (${\text{CuCO}}_3\cdot {\text{Cu(OH)}}_2$), and Calamine (${\text{ZnCO}}_3$) all contain the carbonate group.

Therefore, (A) matches with P, Q, and S.

Next, we search for the Sulphide (${\text{S}}^{2-}$) anion. Among our ores, only Argentite (${\text{Ag}}_2\text{S}$) is a sulphide.

Thus, (B) matches perfectly with T.

Moving on to the Hydroxide (${\text{OH}}^{-}$) anion, we must be careful. Malachite is a basic carbonate, so it contains ${\text{Cu(OH)}}_2$. Bauxite, as we discussed, contains aluminium hydroxide phases represented by ${\text{AlO}}_x{\text{(OH)}}_{3-2x}$. Both of these ores contain hydroxide ions.

So, (C) matches with Q and R.

Finally, we look for the Oxide (${\text{O}}^{2-}$) anion. Bauxite is the only ore in our list that contains oxide ions, as seen in its general formula.

Therefore, (D) matches exclusively with R.

By carefully analyzing the chemical composition of each ore, we have successfully mapped every anion to its corresponding mineral sources.

The final matrix match is: A $\to$ P, Q, S B $\to$ T C $\to$ Q, R D $\to$ R

This problem highlights the importance of knowing not just the primary component of an ore, but its complete chemical nature, especially for mixed ores like Malachite and Bauxite.