Question

Identify the correct pair of mineral and its formula from following.

• A. Baryte - $\mathrm{MgSO_4 \cdot 7H_2O}$
• B. Cryolite - $\mathrm{Na_3AlF_6}$
• C. Galena - $\mathrm{ZnS}$
• D. Epsom salt - $\mathrm{CaSO_4 \cdot 2H_2O}$

Hint:

To remember key ores easily, create simple visual flashcards pairing complex names like Cryolite with their multi-metal formulas like $\mathrm{Na_3AlF_6}$. Remembering that Galena means Lead ($\mathrm{Pb}$) and Baryte means Barium ($\mathrm{Ba}$) lets you eliminate the wrong pairs instantly.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question requires us to evaluate four pairs of mineral names and their chemical formulas to identify the single pair that is scientifically correct.

Step 2: Detailed Explanation:
Let's systematically examine each mineral pair:
Baryte: This mineral is composed of barium sulfate ($\mathrm{BaSO_4}$). The formula provided in option (A), $\mathrm{MgSO_4 \cdot 7H_2O}$, belongs to Epsom salt. Thus, this pair is incorrect.
Cryolite: This is an uncommon mineral identified as sodium hexafluoroaluminate ($\mathrm{Na_3AlF_6}$), traditionally used in the industrial metallurgy of aluminum (Hall-Héroult process). This matching is entirely accurate.
Galena: This is the primary ore of lead, chemically known as lead sulfide ($\mathrm{PbS}$). The formula $\mathrm{ZnS}$ given in option (C) belongs to Zinc Blende (sphalerite). Thus, this pair is incorrect.
Epsom salt: This is magnesium sulfate heptahydrate ($\mathrm{MgSO_4 \cdot 7H_2O}$). The formula $\mathrm{CaSO_4 \cdot 2H_2O}$ provided in option (D) represents Gypsum. Thus, this pair is incorrect.

Step 3: Final Answer:
The correct pair of mineral and its formula is Cryolite - $\mathrm{Na_3AlF_6}$, which corresponds to option (B).