Problem 161 - A Complete Resource Book in Chemistry for JEE Main

Question

The number of sulphide minerals of the following is Cuprite, Argentite, Carnallite, Magnesite, Galena, Black Jack.

Step-by-Step Solution

Answer

There are 3 sulphide minerals: Argentite, Galena, and Black Jack (Sphalerite).

Step 1: Understand the Problem

The task is to identify which of the given minerals are sulphide minerals. A sulphide mineral is composed of sulphur combined with a metal or a semimetal.

Step 2: Identify the Minerals

We list the minerals given in the problem: Cuprite, Argentite, Carnallite, Magnesite, Galena, and Black Jack (Sphalerite).

Step 3: Classify Each Mineral

- Cuprite: An oxide mineral (8{}2O). - Argentite: A sulphide mineral (Ag2{}S). - Carnallite: A chloride mineral (KMgCl2{} 12{}6O). - Magnesite: A carbonate mineral (MgCO0{}). - Galena: A sulphide mineral (PbS). - Black Jack (Sphalerite): A sulphide mineral (ZnS).

Step 4: Count the Sulphide Minerals

From the classification, Argentite, Galena, and Black Jack (Sphalerite) are sulphide minerals. There are three sulphide minerals in total.

Key Concepts

Understanding Mineral Classification

Mineral classification is the process of sorting and categorizing minerals based on their distinct properties. This is a crucial concept in geology and chemistry. Minerals are naturally occurring, inorganic substances with unique chemical and physical properties. They are classified into several groups:

• Silicates: The largest and most common group, these contain silicon and oxygen.
• Oxides: Consist of oxygen and one or more metals, such as cuprite (Cu₂O).
• Sulphides: Comprised of metal cations bonded with sulphide anions, like argentite (Ag₂S) and galena (PbS).
• Carbonates: Include carbonate ion in their structure, such as magnesite (MgCO₃).
• Halides: Consist of a halogen anion combined with a metal, seen in minerals like carnallite (KMgCl₃)

Breaking down mineral classification helps us to understand their chemical compositions and crystal structures better, aiding in various applications from industrial uses to understanding Earth's geology.

Insights into Sulphur Compounds in Minerals

Sulphur compounds are integral to the formation of sulphide minerals. These compounds typically form during specific geological processes where sulphur combines with metals or semi-metals. The result is a sulphide compound.

• Sulphides: Characteristically have metal sulphur bonds, like in argentite (Ag₂S) or galena (PbS). They are major ores for extracting metals such as silver and lead.
• Sulphates: Different from sulphides, these include both sulphur and oxygen (e.g., gypsum - CaSO₄·2H₂O).

Sulphide minerals like sphalerite (ZnS), while useful, can pose environmental challenges. When exposed to oxygen and moisture, they can produce sulfuric acid, contributing to acid mine drainage. Understanding these compounds is important in both mining and environmental management.

The Role of Chemistry Education in Mineralogy

Chemistry education plays a vital role in understanding mineralogy, which is the study of minerals. It provides foundational knowledge that helps students comprehend how different elements combine to form various minerals. Through chemistry:

• Students learn about elemental bonds and molecular structures, aiding in mineral classification.
• It teaches the chemical reactions that lead to the formation and transformation of minerals.
• Chemistry education illuminates real-world applications, such as mining and resource management.

By integrating chemistry concepts with geology, students can better analyze and interpret mineral properties and processes. This comprehensive understanding is crucial for addressing both scientific queries and practical challenges in mineral resource management.