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Difficulty: MediumAluminium: Extraction, Amphoteric Properties, Alloys, and Compounds

Match each aluminium alloy or chemical substance in Column I with its primary industrial composition or application in Column II.

  • DuraluminHigh-strength alloy of aluminium, copper, magnesium, and manganese used in aircraft structural frames
  • MagnaliumLightweight corrosion-resistant alloy of aluminium and magnesium used in balance beams and aircraft parts
  • AlnicoAlloy of aluminium, nickel, cobalt, and iron utilized in manufacturing strong permanent magnets
  • Molten Cryolite (Na3AlF6Na_3AlF_6)Molten solvent added to lower the operating temperature of alumina and improve electrical conductivity

Answer

Duralumin matches with High-strength alloy of aluminium, copper, magnesium, and manganese used in aircraft structural frames; Magnalium matches with Lightweight corrosion-resistant alloy of aluminium and magnesium used in balance beams and aircraft parts; Alnico matches with Alloy of aluminium, nickel, cobalt, and iron utilized in manufacturing strong permanent magnets; Molten Cryolite matches with Molten solvent added to lower the operating temperature of alumina and improve electrical conductivity.
Each substance is correctly paired based on standard chemistry principles: Duralumin is an Al−Cu−Mg−MnAl-Cu-Mg-Mn structural aircraft alloy, Magnalium is an Al−MgAl-Mg lightweight alloy, Alnico is an Al−Ni−Co−FeAl-Ni-Co-Fe magnetic alloy, and molten cryolite (Na3AlF6Na_3AlF_6) lowers the melting temperature of alumina during electrolysis.

Step-by-Step Solution

1
Identify the chemical composition and primary application of Duralumin.
Duralumin contains AlAl, CuCu, MgMg, and MnMn, known for its structural strength in aircraft manufacture.
Copper adds tensile strength to aluminium while retaining low density.
2
Identify the composition and application of Magnalium.
Magnalium is an alloy of AlAl and MgMg, valued for low density and high corrosion resistance.
Magnesium enhances hardness and lightness without increasing susceptibility to oxidation.
3
Determine the composition and use of Alnico.
Alnico consists of AlAl, NiNi, CoCo, and FeFe, used for permanent magnets.
Ferromagnetic elements combined with aluminium create high magnetic retentivity.
4
Determine the role of cryolite in the industrial extraction of aluminium.
Cryolite acts as an electrolytic solvent, lowering the melting point of Al2O3Al_2O_3 and increasing conductivity.
Pure alumina has an extremely high melting point (2050∘C2050^\circ\text{C}); dissolving it in molten cryolite reduces energy consumption.

Key Concept

Industrial extraction of aluminium and compositions/applications of its major alloys
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Topics

Aluminium: Extraction, Amphoteric Properties, Alloys, and Compounds

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