Class 10 Chemistry Chapter 7
Metallurgy 
Important Questions

Here, you'll discover significant inquiries pertaining to Chapter 7: Metallurgy for ICSE Class 10 Chemistry. These inquiries are carefully designed to aid students in preparing for the ICSE Class 10 Chemistry Examination in 2023–24. Engaging with different question formats allows students to address uncertainties, improve their exam preparedness, boost their self-assurance, and polish their ability to solve problems.

Introduction

In Chapter 7 of  ICSE Class 10  Metallurgy , you will explore the concept of Metallurgy. This chapter covers the following topics:

• Understanding the terms "Mineral" and "Ore."
• Identifying common ores of iron, aluminium, and zinc.
• Methods for ore dressing, including hydrolytic techniques, magnetic separation, and froth flotation.
• Converting concentrated ore into its oxide form through processes like roasting and calcination, along with definitions and examples supported by equations.
• Examining the reduction of metallic oxides, where some can be reduced by substances such as hydrogen, carbon, and carbon monoxide (e.g., copper oxide, lead (II) oxide, iron (III) oxide, and zinc oxide), while others cannot (e.g., Al₂O₃, MgO), based on their position in the activity series.
• Understanding the electrolysis of active metals like sodium, potassium, and calcium .
• A brief overview of electro-refining.
• The chemical method for purifying bauxite using NaOH, known as the Baeyer's Process.
• Electrolytic extraction, specifically the Hall Heroult's process, including the structure of the electrolytic cell, its various components (electrolyte, electrodes), and electrode reactions.
• Exploring materials such as stainless steel, duralumin, brass, bronze, and fuse metal/solder.

This chapter provides a comprehensive understanding of metallurgical processes, including their principles, methods, and applications.

What is Metallurgy ?

In the ICSE Class 10 Chemistry Chapter 7 “Metallurgy," metallurgy is a structured process used to acquire metals in their pure form. Minerals are compounds containing metal elements combined with elements like soil, limestone, sand, and rocks. The cost-effective extraction of metals from these mineral combinations, known as ores, demands minimal resources and effort. Within the furnace, a component introduced into the mixture to remove unwanted impurities, referred to as gangue, is termed flux. Metallurgy encompasses both the refining of metals and the formation of alloys.

Class 10 Chemistry Chapter 7 Metallurgy Important Questions and Answers

Q1. The metals zinc and tin are present in the alloy :

Options

(a) Solder
(b) Brass
(c) Bronze
(d) Duralumin

Ans. (c)

Explanation:
Bronze is an alloy composed primarily of copper, along with varying proportions of tin. It's one of the earliest alloys developed by humans and has been used for thousands of years due to its desirable properties, such as durability, malleability, and resistance to corrosion. The addition of tin to copper in bronze improves the hardness and strength of the metal, making it suitable for various applications, including tools, weapons, sculptures, and decorative objects. While zinc is not a primary component of bronze, it can sometimes be present in small amounts as an impurity or as an intentional addition for specific purposes.

Q2. Froth floatation process for the concentration of ores is an illustration of the practical application of :

Options

(a) Adsorption
(b) Absorption
(c) Sedimentation
(d) Coagulation

Ans. (a)
Explanation:
Froth flotation process for the concentration of sulphide ores illustrates the application of adsorption because in this process ores are adsorbed on the surface of the froth collector.

Q3. During the extraction of aluminium, cryolite and fluorspar are added to alumina. Why?

Explanation:
Cryolite and fluorspar are added to alumina :
(i) To lower the melting point of aluminium.
(ii) To make alumina a good conductor of electricity.
(iii) Cryolite acts as a solvent for alumina.

Q4. Explain why in the electrolysis of alumina using the Hall Heroult’s process the electrolyte is covered with powdered coke.

Explanation:
The Hall-Heroult process is the electrolytic process of alumina to obtain molten aluminium. In the Hall-Heroult process, powdered coke is used to reduce heat loss by radiation and prevent the burning of anode. In the Hall-Heroult process, pure alumina is mixed with cryolite. This results in a lowering of the melting point of the mixture, so its ability to conduct electricity increases. A steel vessel with a lining of carbon and graphite is used in the process.The carbon lining acts as cathode and carbon lining acts as anode. After passing electricity through the electrolyte consisting of a carbon electrode, oxygen is formed at anode. This leads to the formation of carbon monoxide and carbon dioxide by reacting the formed oxygen with the carbon anode. In this process, for every 2 units of aluminium formed 1 unit of carbon anode is burned. To prevent this burning of anode we use powdered coke as a covering for the electrolyte.

Q5. (a) With reference to the reduction of copper oxide, iron(II) oxide, lead(II) oxide and magnesium oxide by hydrogen; place the oxides in increasing order of reduction, i.e., first the oxide that is most difficult to reduce; and at last, the oxide that is most easy to reduced. 
(b) (1) What is the type of bonding expected in metallic chloride? 
(2) If fused metallic chloride is electrolysed, at which electrode the metal will be obtained. 
(3) What metallic property is shown by the non-metal graphite?

Explanation:
(a) Magnesium oxide, Iron (II) oxide, Lead (II) oxide, and then copper (II) oxide
(b) (1) Ionic bonding (or electrovalent bonding) is expected in metallic chlorides. Metals transfer their excess electrons to nonmetals that are electron deficient. Thus, both attain stability and form an ionic or electrovalent bond. Example: in sodium chloride, sodium donates its one extra electron to chlorine. Therefore, sodium loses one electron and chlorine gains one electron, attaining stability in the process and forming an ionic bond.

(2) Fused metal chloride contains free ions: metal cations and chloride anions. If fused metal chloride is electrolyzed, the positively charged metal ions (cations) are attracted toward the cathode (negatively charged electrode). These metal ions obtain electrons from the cathode and get reduced to metal atoms. Example: During the electrolysis of fused sodium chloride, sodium ions are attracted to the cathode. 
(3) Even though graphite (an allotrope of carbon) is a non-metal, it is a good conductor of electricity. Thus, graphite conducts electricity and resembles metal in terms of its electrical conductance.

ICSE Class 10 Chemistry Chapter wise Important Questions

Conclusion

The study of metallurgy in ICSE Class 10 Chemistry offers valuable insights into the fascinating world of metals and their extraction. From the identification of minerals and ores to the various methods of ore concentration and purification, this chapter equips you with essential knowledge about metallurgical processes.To further solidify your grasp of these concepts and enhance your preparation, consider exploring additional practice resources. oswal.io offers an extensive array of questions and resources designed to complement your learning journey. These materials provide valuable opportunities to test your knowledge, hone your skills, and reinforce the principles of metallurgy covered in this chapter.

Frequently Asked Questions

Q1 : List the different techniques used in ore enrichment.

Ans: The different techniques used in ore enrichment include:

• Electromagnetic separation
• Froth flotation method
• Hydraulic washing method

Q2: Differentiate between roasting and calcination.

Ans:  Roasting involves heating ore in the presence of air, whereas calcination entails heating ore without the presence of air.

Q3 : What is the purpose of purifying extracted metals?

Ans: The metal obtained through the extraction process from ores often carries impurities like carbon, silicon, phosphorus, and similar substances.The choice of refining method for a particular metal depends on both its inherent characteristics and the types of impurities present. Consequently, a range of techniques is utilised for this purpose. Among these methods, electrolysis stands out as highly significant and yields exceptionally pure metals.

Q4 : What is the purpose of reduction?

Ans:  Reduction is carried out to obtain the metal from the ore. Typically, reduction is achieved through one of the following methods:

• Using coke.
• Through the lawful decomposition of molten salts.

Q5 : Define Smelting.

Ans: Smelting involves heating ore to extract a fundamental metal and is a form of extractive metallurgy. Various base metals like silver, iron, copper, and others are obtained from their ores through this process.