Chemistry ยท Science General
Metallurgical Processes
1,436 Questions
This section explores key metallurgical processes including ore concentration, pyrometallurgy, and metal refining. It also covers corrosion and the properties of refractory materials. These chemistry questions are relevant for engineering and science entrance tests.
Pyrometallurgy furnacesMetal refining techniquesCorrosion protection methodsOre concentrationAuto reduction process
Metallurgical Processes Questions
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of decrsase in enthalpy
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of decrease in entropy
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of increase in enthalpy
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of increase in entropy
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oxygen and sulphur
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oxygen and nitrogen
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sulphur and chlorine
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Zr and Ti
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bromine
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chlorine
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carbon
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iodine
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purification of ore
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purification of metal
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reduction of metal oxide
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conversion of sulphide into oxide
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it is thermodynamically not feasible
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the temperature requirement is high
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magnesium is not a good reducing agent
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it is evident from Ellingham diagram
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cast iron
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pig iron
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wrought iron
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nickel steel
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they are inert
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they are less reactive
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they are rendered passive by oxide film
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they are difficult to oxidise
C
Correct answer
Explanation
Metals such as Cr and Al do not dissolve in concentrated nitric acid because of the formation of a passive film of oxide on the surface of metals.
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polarizability
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physisorption
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chemisorption
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dissociation
C
Correct answer
Explanation
Chemisorption is a sub-class of adsorption, driven by a chemical reaction occurring at the exposed surface. A new chemical species is generated at the adsorbant surface e.g., corrosion, metallic oxidation. The strong interaction between the adsorbate and the substrate surface creates new types of electronic bonds - ionic or covalent, depending on the reactive chemical species involved.
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Peptization
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Oxidation
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Reduction
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Hydrolysis
C
Correct answer
Explanation
A number of metals such as silver, gold and platinum, have been obtained in colloidal state by treating the aqueous solution of their salts, with a suitable reducing agent such as formaldehyde, phenyl hydrazine, hydrogen peroxide, stannous chloride etc..
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Hydration and carbonation
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Hydrolysis and oxidation
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Leaching and oxidation
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Hydration and calcification
C
Correct answer
Explanation
Laterite forms in tropical regions with high rainfall through intense leaching of silica and soluble minerals, leaving behind iron and aluminum oxides. The oxidation process gives laterite its characteristic red color. Hydration, carbonation, hydrolysis, and calcification contribute to soil formation but leaching+oxidation is most critical for laterite.
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Used in electroplating
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Used in the manufacturing of sodium
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Used in the manufacturing of silver
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Used in the refining of copper
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cathode
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anode
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electrolyte
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circuit
A
Correct answer
Explanation
In electroplating, the object to be coated is made the cathode (negative electrode). Metal ions from the anode solution deposit onto the cathode surface.
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Only A
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Only B
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Only C
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Only A and B
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Only B and C
D
Correct answer
Explanation
The substances that are capable of withstanding very high temperatures without melting or becoming soft are called refractory materials like- SiC (carborundum), Al2O3, SiO2, etc.
Blast furnace is used or the smelting of iron, copper and lead ores.
Calamine (ZnCO3) is the ore of zinc while casseterite (SnO2) is the ore of Sn.
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high density, due to closed packing of atoms
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high polish
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reflection of light due to the presence of free electrons
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absorption of light due to the presence of cavities
C
Correct answer
Explanation
The metallic luster (shine) is caused by free electrons in the metal that reflect light. When light strikes the metal surface, these delocalized electrons vibrate and re-emit the light, creating the characteristic shine. This property is related to electrical and thermal conductivity of metals.