Metals and Its Ores MCQ Quiz - Objective Question with Answer for Metals and Its Ores - Download Free PDF

CONCEPT:

Copper Ores and Their Chemical Composition

• Copper is commonly found in nature in the form of various ores, from which it is extracted.
• The most important and abundant copper ore is Chalcopyrite (CuFeS₂).
• It is a sulfide mineral and the chief source of copper worldwide, including in Madhya Pradesh (notably in the Malanjkhand copper mines).

EXPLANATION:

• CuFeS₂ (Chalcopyrite): The most important copper ore; occurs extensively in Madhya Pradesh; major source for commercial copper extraction.
• Cu₂O (Cuprite): An oxide ore of copper; less abundant and not the primary source in India.
• CuS (Covellite): A minor sulfide ore of copper; less economically important than chalcopyrite.
• CuSO₄ (Copper sulfate): A laboratory and industrial chemical; not a naturally occurring ore used for copper extraction.

Therefore, CuFeS₂ (Chalcopyrite) is the correct chemical formula of the primary copper ore found in Madhya Pradesh.

CONCEPT:

Minerals Used in the Extraction of Aluminium

• Aluminium is extracted from its principal ore known as Bauxite (Al₂O₃·2H₂O).
• Bauxite is a sedimentary rock rich in aluminium hydroxide minerals and is the primary source of aluminium worldwide.
• The extraction process involves purification of bauxite to obtain alumina (Al₂O₃), followed by electrolytic reduction (Hall-Héroult process) to produce aluminium metal.

EXPLANATION:

• Bauxite: Main ore of aluminium; Madhya Pradesh has rich reserves, especially in areas like Amarkantak and Balaghat; directly used in aluminium production.
• Iron ore: Used for extraction of iron, not aluminium.
• Manganese: Used in steel making and batteries, not in aluminium extraction.
• Copper: Extracted from ores like chalcopyrite and not related to aluminium production.

Hence, Bauxite is the key mineral found in Madhya Pradesh that is used in the extraction of aluminium.

CONCEPT:

Raw Materials for Glass Manufacturing

• Glass is primarily made by heating a mixture of raw materials until it melts into a liquid and then cooling it into a rigid, non-crystalline form.
• The most essential component in this mixture is silica (SiO₂), commonly in the form of silica sand, which forms the structural framework of glass.
• Other ingredients like soda (sodium carbonate) and lime (calcium oxide) are added to modify the properties of glass.

EXPLANATION:

• Silica sand: The main raw material; provides the glass-forming oxide (SiO₂). It typically makes up 70–75% of the glass batch.
• Sodium carbonate: Used as a flux to lower the melting point of silica, but it is not the primary ingredient.
• Lime: Added to improve the durability of glass but used in smaller proportions.
• Bauxite: Source of aluminum, used in the production of aluminum and alumina—not used in glass manufacturing.

Therefore, Silica Sand is the primary raw material used in the manufacturing of glass due to its high silicon dioxide content.

CONCEPT:

Chemical Composition of Cement and Strength Contribution

• Ordinary Portland Cement (OPC) is mainly composed of oxides of calcium, silicon, aluminum, and iron.
• Upon hydration, the strength of cement is largely due to the formation of calcium silicate hydrate (C-S-H) gel.
• The primary strength-giving compounds are Tricalcium Silicate (C₃S) and Dicalcium Silicate (C₂S), both of which are forms of calcium silicates.

EXPLANATION:

• Calcium silicate (CaSiO₃): Key component responsible for the strength of cement. On hydration, it forms calcium silicate hydrate (C-S-H), which imparts strength and durability.
• Calcium oxide (CaO): Acts as a raw material in the manufacture of cement but does not directly contribute to the strength after hydration.
• Magnesium oxide (MgO): Present in minor quantities; excessive amounts may lead to unsoundness in cement.
• Iron oxide (Fe₂O₃): Contributes to the color and acts as a flux in the kiln but is not primarily responsible for strength.

Hence, Calcium Silicate is primarily responsible for the strength of cement through the formation of C-S-H gel during hydration.

CONCEPT:

Minerals Used in Steel Production

• Steel production requires key raw materials such as iron ore, manganese, limestone, and sometimes coking coal.
• Manganese is essential in steelmaking as it acts as a deoxidizer and helps remove sulfur and oxygen impurities.
• It also improves the hardness and strength of steel alloys.

EXPLANATION:

• Manganese: Madhya Pradesh is one of the leading producers of manganese ore in India. It is widely used in steel production as an alloying agent and a purifier.
• Zinc: Mainly used in galvanizing steel, but Madhya Pradesh is not a major producer of zinc. Major reserves are found in Rajasthan.
• Bauxite: Used in aluminium production, not steel. Madhya Pradesh has some bauxite reserves but it is not its primary industrial mineral.
• Copper: Used in electrical industries; Madhya Pradesh has copper reserves, especially in Malanjkhand, but it is not significant in steel production.

Therefore, Madhya Pradesh is a major producer of Manganese, which is a key mineral used in the steel industry.

The correct answer is Bauxite.Key Points

• Bauxite is an aluminium-rich sedimentary rock formed from laterite soil.
• It is found in tropical or subtropical regions.
• Bauxite is used for the production of Aluminium.
• Bauxite is a non-ferrous metallic mineral that is used in the manufacturing of aluminium.
• Bauxite is found mainly in tertiary deposits and is associated with laterite rocks.

 Important Points

• Odisha is the largest bauxite-producing state in India.
• More than half of India's bauxite deposits are found in Odisha.
• Bauxite is an important mineral used in the production of aluminium.

 Additional Information

Important ores:

Concept:

Metal: It's an element that forms positive ions (cations) and has metallic bonds.

Physical Properties of Metals: 

• Ductility: Metals are ductile as they can be drawn into thin wires.
• Lustre: Metals have a shiny surface which is called metallic lustre.
• Hardness: Metals are generally hard and remain solid at room temperature. 
• Malleability: Metals are malleable, that is they can be beaten into thin sheets.
• Conductivity: Metals are good conductors of heat and electricity.
• ​Sonorous: All metals, except mercury, are sonorous i.e. they produce a sound on striking a hard surface. 
• Melting and Boiling Points: Metals have high melting and boiling points. 

Explanation:
Non-metals: They are opposite metals.

• They are neither malleable nor ductile.
• They are bad conductors of heat and electricity, except for graphite, which conducts electricity.
• Nonmetals generally have a low density as compared to metals.

Additional Information

Some important facts about metals:

The correct answer is Cinnabar - Nickel.Key Points

• Cinnabar is a mercury sulfide ore and not a nickel ore.
• Bornite is an important copper ore that is also known as peacock ore due to its iridescent colors.
• Magnetite is a type of iron ore that is strongly magnetic and is used as a source of iron in steel making.
• Galena is a lead sulfide mineral that is the most important source of lead ore.

Additional Information

• Hematite is another important iron ore that is commonly found in sedimentary rocks and is used in the production of iron and steel.
• Chalcopyrite is a copper iron sulfide mineral that is the most important copper ore mineral.
• Sphalerite is a zinc sulfide mineral that is the most important zinc ore mineral.

The correct answer is Mercury.

Key Points

• A heavy, silvery d-block element, mercury is the only metallic element that is liquid under standard temperature and pressure conditions;
• The only other element that is liquid under these conditions is bromine, although metals such as cesium, gallium, and rubidium melt just above room temperature.

Additional Information

• Sodium:
  • Sodium is part of the alkali metal family along with lithium and potassium.
  • As one of the two ingredients of our table salt is its greatest reputation.
• Calcium:
  • Calcium with atom number 20 is represented in the periodic table by the symbol Ca.
  • Calcium (Ca) is an important element that makes our bones strong and able to withstand our loads.
• Lithium:
  • Lithium is a chemical element that appears first in the alkalis of the periodic table.
  • It is the lightest solid metal.

The correct answer is Bell Metal.

• Bell Metal alloy consists of copper and tin.

Key Points

• Bell metal is a hard alloy used for making bells and similar instruments, such as cymbals. 
• It is a form of bronze with a higher tin content, approximately a 4:1 ratio of copper to the tin.
• It is made of 80% copper and 20% tin (Sn) with some amount of Zinc and Lead.
• Bell metal is known for its resonance and attractive sound.

Additional Information

• ​Soft solder is an alloy of tin and lead.
• Hard solder is an alloy of copper and zinc.
• Rose's metal is an alloy of bismuth, lead and tin with 50% bismuth, 25–28% lead and 22–25% tin.
• German Silver is an alloy of copper, zinc and nickel.

Important Points

Some other important alloys are:

• German Silver - Cu + Zn + Ni
• Gun Metal - Cu + Sn + Zn + Pb
• Solder - Pb + Sn
• Brass - Cu + Zn
• Stainless steel - Fe + Cr + Ni + C​

The correct answer is option 1.

Concept:

• The Earth's crust is composed of a variety of elements, but some elements are more abundant than others.
• The composition of the Earth's crust has been studied extensively, and it is well-known that certain elements are the most abundant.
• These elements are determined based on their percentage by weight in the Earth's solid surface.

Explanations: 

• Al and Fe (Aluminum and Iron): Aluminum and iron are indeed among the most abundant elements in the Earth's crust.
• Aluminum is the most abundant metal, while iron is the fourth most abundant element. This option aligns with the concept.
• Al and Cu (Aluminum and Copper): Copper is not one of the most abundant elements in the Earth's crust. Copper is less abundant than both aluminum and iron. This option is not accurate.
• Fe and Cu (Iron and Copper): Copper is not among the most abundant elements in the Earth's crust. Iron is one of the most abundant elements, but copper is relatively less abundant. This option is not accurate.
• Cu and Ag (Copper and Silver): Copper is more abundant than silver in the Earth's crust, but neither copper nor silver are among the most abundant elements. This option is not accurate.  

The correct answer is Option 1: Al and Fe (Aluminum and Iron). 

The correct answer is Cu + Sn.

Key Points

• Bronze is the mixture of the metals tin and copper.
• The bronze alloy was made as early as the Harappan age.
• An alloy is considered a homogeneous mixture because, by definition, a homogeneous mixture has the same uniform appearance and composition throughout.
• Since an alloy is a mixture of two or more metals or a mixture of a metal with some other element, and these mixtures are uniform throughout, they fit the definition of being homogeneous.

Additional Information

The correct answer is All the alkali metals have two valence electrons.

Key Points

• Group 1 elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr) are known as alkali metals. Hence option 3 is correct.
• They are also known as s-block elements.
• The general electronic configuration of group 1 elements is ns1. It means they have only one electron in outermost shell. Hence option 4 is NOT correct.
• All alkali metals are soft, silvery white, with low densities, melting temperatures, and boiling points. Hence option 1 is correct.
• Melting point decreases down the groups in a periodic table.
• The ionization enthalpies of the alkali metals are considerably low and decrease down the group from Li to Cs. Hence option 2 is correct.
• Ionization Enthalpy is the minimum amount of energy required to remove a valance electron from an isolated gaseous atom (X) in its ground state.

Additional Information

• Due to ns1 electronic configuration, they have weak metallic bonding which explains their physical and chemical characteristics
• As we move down the group, this outer shell electron travel further from the nucleus.
• As a result, the atomic radii increases.
• As the ions get larger the distance between the bonding electrons and the positive nucleus gets larger and reduces the overall attraction between the two.

The correct answer is Tin.

Key Points

• Although tin is used in various alloys and has its own unique characteristics, it is not a common component of stainless steel.
  • Adding tin to stainless steel is not common and is not considered a standard ingredient in stainless steel production.
• Stainless steel is primarily composed of iron, along with chromium, nickel, and other elements. 
  • Chromium provides corrosion resistance to steel.
  • It exhibits exceptional corrosion resistance due to the formation of a very thin layer of Cr₂O₃ on the surface.
  • Nickel is usually added to stainless steel to increase its strength and hardness. It also improves corrosion resistance, especially in acidic environments.
  • An important type of stainless steel is often described as 18/8 steel where the chromium and nickel percentages are 18 and 8 respectively.

The correct answer is Hematite.

Key Points

•  Magnetite is a mineral and the main iron ore.
• Magnetite, hematite, and limonite are iron ores containing 72.04%, 69.9%, 55% iron respectively.
• Mainly four types of iron ore are found in India –
  • (i) Magnetite
  • (ii) Hematite
  • (iii) Limonite
  • (iv) Siderite

Important Points

•  Among iron ores, magnetite ore is the best quality iron ore. But it is found in very small quantities in India.
• Bauxite is an ore of aluminum, not iron.
• Cinnabar is a toxic mercury sulfide mineral with a chemical composition of HgS. It is the only important ore of mercury.