Metals and Its Ores MCQ Quiz in मल्याळम - Objective Question with Answer for Metals and Its Ores - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

The correct answer is option 2 that is Carbon.

Concept:

• In the context of mining, metallurgy, and materials processing, the phrases "impurities" and "gangue" are frequently used to indicate undesirable elements or components that are present alongside the desired material (typically ore) and must be separated from or eliminated.
• Impurities are substances or elements that are present in a material but do not make up the composition it is intended to have. 
• together an ore deposit, gangue specifically refers to the minerals or rocks that are mixed together with the ore minerals. 

Explanation:

• ​Pig iron contains a variety of impurities, including different levels of carbon, silicon, sulfur, phosphorus, and manganese. Due to its frequent presence in the iron ore and coke used in the blast furnace process.
•  Pig iron is the intermediate product of smelting iron ore with coke and limestone in a blast furnace. It contains varying amounts of impurities, with carbon being one of the primary impurities.
• The carbon content in pig iron can range from around 3% to 4.5%, making it the most abundant impurity in most cases. Other common impurities in pig iron include silicon, sulfur, phosphorus, and manganese, but their concentrations are usually lower compared to carbon.
• Pig iron is the end product of the first step in the manufacturing of iron, which is commonly done in a blast furnace.
• It is the end result of heating iron ore, carbon coke, and limestone all at once in a blast furnace. 
• Pig iron contains a number of important impurities, including carbon (C), silicon (Si), sulfur (S), phosphorus (P), and manganese (Mn).
• These impurities are referred to as gangue elements, and they can have an impact on the characteristics of pig iron.

The Correct Answer is Wrought Iron.

Key Points

•  Iron​
  • Iron is generally of the following types:-
  • Pure iron has a Fe content of 99.85% with a very small amount of impurities.
  • It is silvery-colored metal and is soft in nature.
  • Wrought iron is a commercial carbon and has a very low carbon content of 0.10%.
  • It is a very pure iron where the iron content is of the order of 99.5%.
  • It is also called commercially pure Iron.
  • Wrought iron is a pure form of Fe with a small amount of slag (CaSiO3) that gives resistance to progressive corrosion.
  • Cast iron has major elements that contain iron, carbon, and silicon.
  • It has higher carbon and silicon content than steel.
  • Pig iron is an iron-carbon alloy in which contains carbon and other elements such as silicon, manganese, sulphur, phosphorous etc.
  • Stainless steel is a group of iron-based alloy that contains 11% chromium.
  • It is resistant to rust due to the presence of chromium.​

Important Points

• Iron is an element with Atomic no. 26 and is Transition metal.
• Its atomic mass is 56 and is denoted by the symbol Fe.
• Iron ores are most abundant in the earth’s crust.
• The pure form of elements is those which has maximum percentage of element and has very low impurities.​

Additional Information

• Wrought Iron is produced by re-melting pig iron and some small amount of silicon, sulphur, or phosphorus may be present. It is tough, malleable and ductile and can easily be forged or welded.
• It cannot however take the sudden shock.
• Chains, crane hooks, railway couplings and such other components may be made of this iron.
• Wrought iron can never be cast.

Concept:

• Metals are the elements with valence electrons either 1 or 2 in general.
• For example, alkali metals (sodium, potassium), and alkaline earth metals (magnesium, calcium).

Explanation:

Element X

• Element X has electronic configuration 2,8. Its atomic number becomes 10. It is neon. It has completely filled valence shell.
• It comes under the class of inert gases.
• Hence element X is a noble gas element it is neither metal nor non-metal. It's a gas.

Element Y

• Y has an electronic configuration as 2,8,7.
• Its atomic number becomes 2+8+7=17 and it is chlorine.
• It has 7 electrons in its valence shell.
• It can easily gain one electron and attain 8 electrons in its valence shell. 
• Attaining 8 electrons in the valence shell represents the stable inert gas configuration.
• For that purpose, Chlorine gains electrons. But metals lose electrons easily.
• Hence element Y is not a metal.

Element Z

• The element Z has an electronic configuration is 2,8,2.
• It has two valence electrons. Its atomic number is 12. The element is magnesium.
• It can lose those two electrons easily and becomes Mg²⁺ and attain 8 electrons in its valence shell.
• Thus, Z is a metal.

Hence, we can conclude that element Y is a non-metal and element Z is a metal. 

The correct answer is Mercury.

In News

• Cinnabar is prominently known as the primary ore of mercury.

Key Points

• Cinnabar is a bright red mineral consisting of mercury sulfide (HgS).
• It is the most common source ore for refining elemental mercury.
• Cinnabar has been used historically for its mercury content and for its vibrant red pigment.
• Mercury
  • Symbol - Hg
  • Atomic number - 80
  • State at room temperature - Liquid
  • Uses - Thermometers, barometers, fluorescent lighting, and amalgams for dental restoration.

Additional Information

• Cinnabar
  • Composition - Mercury(II) sulfide (HgS)
  • Color - Bright red to brick-red
  • Hardness - 2 to 2.5 on Mohs scale
  • Crystal system - Trigonal
  • Used historically as a pigment called vermilion.
• Mercury (Element)
  • Mercury is the only metal that is liquid at standard conditions for temperature and pressure.
  • It is highly toxic and exposure can lead to mercury poisoning.
  • Found in - Cinnabar, living organisms, coal, and mineral ores.
  • Environmental Concerns - Mercury pollution is a significant environmental issue.

The correct answer is Ductility.

Key Points

• Ductility is the ability of a material, specifically metals, to be stretched into thin wires.
• This property allows metals to undergo significant plastic deformation before rupture or failure.
• Metals like gold, silver, and copper are highly ductile and can be drawn into very thin wires without breaking.
• Ductility is a critical factor in metalworking processes, including wire drawing, forging, and extrusion.
• The measure of a material's ductility is often expressed as a percentage of elongation or the reduction in area before fracture in a tensile test.

Additional Information

• Malleability is another property related to ductility, which refers to the ability of a material to be hammered or rolled into thin sheets.
• While ductility deals with tensile stress (stretching), malleability deals with compressive stress (hammering or rolling).
• Both properties are essential in the industrial application of metals for manufacturing and engineering purposes.
• Materials with high ductility and malleability are often preferred in industries that require extensive shaping and forming, such as automotive and aerospace industries.
• Understanding the ductility of metals helps in selecting the right materials for specific applications, ensuring reliability and efficiency in the final product.

The correct answer is Gangue.

Key Points

• Gangue refers to the unwanted materials or impurities such as sand, soil, or rocks present in an ore.
• It is an essential concept in the mining and mineral processing industry, where the primary goal is to separate valuable minerals from gangue.
• Efficient removal of gangue is crucial for the economic extraction of metals and for minimizing waste.
• The process of separating gangue from ore is known as beneficiation, which may involve techniques like crushing, grinding, and various separation methods.
• Understanding the nature of gangue is important for developing effective ore processing strategies and for improving the overall yield of the target mineral.

Additional Information

• Ore
  • An ore is a naturally occurring solid material from which a metal or valuable mineral can be extracted profitably.
  • Ores typically contain both the target mineral and gangue materials.
• Beneficiation
  • This is the process of concentrating the valuable minerals in the ore and removing the gangue.
  • Common beneficiation methods include gravity separation, flotation, and magnetic separation.
• Smelting
  • Smelting is a metallurgical process involving the heating and melting of ore to extract a base metal.
  • It is often used after beneficiation to further purify the metal extracted from the ore.

Concept:

• Alloys are homogeneous mixtures of two or more metals.
• Sometimes non-metals are also mixed together.
• These alloys are used in day-to-day life in various ways.

Explanation:

Solder:

• Solder is a mixture of 60% tin and 40% lead.
• Hence it is not an iron alloy.

Stainless steel

• It is an alloy of iron, chromium, nickel and some very less amount of carbon.
• Hence this is an iron alloy.

Alnico

• It is an alloy of iron aluminium, nickel and cobalt.
• So, this is also an iron alloy.

Nichrome

• It is an alloy of nickel(maximum amount), chromium along with traces of iron.
• So this also comes under the class of iron alloys.

Hence We can conclude that the correct answer is Solder.

The correct answer is - 2) Malachite

Concept:

Ore - Ores are naturally occurring rocks that contain sufficient minerals with important elements including metals or metal compounds.

• Metal ores are generally oxides, sulfides, silicates, carbonates, etc.
• Metals are not always found in the free state.
• Metals like potassium, sodium, magnesium, calcium, etc are found in a combined state.
• From these metal compounds, a pure form of metal is extracted.

​

Explanation:

Copper Ore - Principal forms in which copper ores are found include native copper, porphyry copper, massive deposits, and mixed ores.

• The concentration of copper in ores averages only 0.6%, and most commercial ores are sulfides, especially chalcopyrite (CuFeS₂), bornite (Cu₅FeS₄), and, to a lesser extent, covellite (CuS) and chalcocite (Cu₂S).
• Cuprite is an oxide mineral composed of copper(I) oxide Cu₂O and is a minor ore of copper.
• Malachite is a copper ore consisting mainly of basic copper(II) carbonate.
• Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. 

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%, and 55% iron respectively.
• Mainly four types of iron ore are found in India –
  • Magnetite
  • Hematite
  • Limonite
  • Siderite

Additional Information

• Haematite
  • Reddish;  68-70 per cent metallic content.
  • Found in Dharwad and Cuddapah rock systems of peninsular India.
  • 80 per cent of haematite reserves are in Odisha, Jharkhand, Chhattisgarh and Andhra Pradesh.
  • In the western section, Karnataka, Maharashtra and Goa have this kind of ore.
• Magnetite
  • Black ore; best quality ore. 70 to 72 per cent metallic content.
  • Dharwad and Cuddapah systems.
  • Have Magnetic quality.
  • Found in Karnataka, Andhra Pradesh, Rajasthan, Tamil Nadu and Kerala.
• Limonite
  • Inferior ores; yellowish in colour; 40 to 60% iron metal.
  • Damuda series in Raniganj coal field, Garhwal in Uttarakhand, Mirzapur in Uttar Pradesh and Kangra valley of Himachal Pradesh.
• Siderite
  • ‘Iron carbonate’; inferior quality; less than 40 per cent iron.
  • Contains many impurities, and mining is not economically viable.
  • However, it is self-fluxing due to the presence of lime.

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 aluminium, not iron.
• Cinnabar is a toxic mercury sulfide mineral with a chemical composition of HgS. It is the only important ore of mercury. 

The correct answer is FeO + SiO2  → FeSiO3
Key points - 

• Slag formation is a common process during the extraction of metals in pyrometallurgical procedures such as iron or steel manufacture, or during the smelting of ores.
• Slag refers to the byproduct, typically consisting of various metal oxides, silica, and other fluxing materials that are added intentionally to the molten metal to remove impurities.
• The most common impurity in iron extraction is silica (SiO₂).

Explanation-

• The reaction in a blast furnace for iron extraction involving slag formation might look something like this:
• Fe₂O₃ + CO → FeO(s) + CO₂(g)
• Here, the Ferric oxide decomposes under high heat into ferrous oxide(FeO) and carbon dioxide gas.
• The ferrous oxide(FeO) then reacts with silica, to form Iron silicate (FeSiO3) or slag.
• FeO(s) + SiO₂(s) → FeSiO₃
• This iron silicate is less dense than the molten iron and so floats on its surface, allowing for easy removal.
• In summary, slag formation is a crucial part of the metal extraction process, enabling impurities in the metal ores to be effectively removed and isolated from the pure molten metal.
• The specific reactions involved will depend on the nature of the flux used and the impurities present.