Question

Identify the sets of ores of the same metal I. Kernite, Kaolinite II. Magnetite, Siderite III. Zincite, Calamine IV. Cuprite, Malachite

• A. II, III only
• B. I, II, III only
• C. II, III, IV only
• D. III, IV only \bigskip

Hint:

Remember common ore-metal pairs: Magnetite, Siderite $\rightarrow$ Iron Zincite, Calamine $\rightarrow$ Zinc Cuprite, Malachite $\rightarrow$ Copper Kaolinite $\rightarrow$ Aluminium mineral

Answer 1

The Correct Option is C

Concept: Different minerals and ores may contain the same metal in different chemical forms. To answer such questions, we identify the principal metal present in each ore and then compare them.

Step 1: Examine Pair I: Kernite and Kaolinite.
Kernite is an ore of boron. \[ Na_2B_4O_7 \cdot 4H_2O \] Kaolinite is an aluminium silicate mineral. \[ Al_2Si_2O_5(OH)_4 \] Thus, these ores do not contain the same metal. \[ \text{Pair I is incorrect} \]

Step 2: Examine Pair II: Magnetite and Siderite.
Magnetite: \[ Fe_3O_4 \] Siderite: \[ FeCO_3 \] Both are important ores of iron. \[ \text{Pair II is correct} \]

Step 3: Examine Pair III: Zincite and Calamine.
Zincite: \[ ZnO \] Calamine: \[ ZnCO_3 \] Both are ores of zinc. \[ \text{Pair III is correct} \]

Step 4: Examine Pair IV: Cuprite and Malachite.
Cuprite: \[ Cu_2O \] Malachite: \[ CuCO_3 \cdot Cu(OH)_2 \] Both are ores of copper. \[ \text{Pair IV is correct} \]

Step 5: Identify all correct pairs.
Correct pairs are: \[ II,\ III,\ IV \] Hence the required answer is \[ \boxed{\text{II, III and IV only}} \]