Match each aluminium alloy or extraction reagent on the left with its correct composition,… — JAMB UTME

Match each aluminium alloy or extraction reagent on the left with its correct composition, primary industrial application, or function on the right.

DuraluminComposition of $Al$ , $Cu$ , $Mg$ , and $Mn$ ; used in aircraft body construction due to high tensile strength and low density.
MagnaliumComposition of $Al$ and $Mg$ ; light and resistant to corrosion, used in making scientific balance beams and light instruments.
AlnicoComposition of $Al$ , $Ni$ , $Co$ , and $Fe$ ; used in manufacturing powerful permanent magnets.
Cryolite ( $Na_3AlF_6$ )Molten solvent added during Hall-Héroult extraction to lower the melting point of pure alumina from $2050^\circ C$ to about $950^\circ C$ and increase electrical conductivity.

Duralumin matches with the composition of

Al

Cu

Mg

Mn

used in aircraft bodies; Magnalium matches with the composition of

Al

Mg

used in balance beams; Alnico matches with the composition of

Al

Ni

Co

Fe

used in permanent magnets; Cryolite matches with the molten solvent that lowers the melting point of alumina in extraction.

Each item correctly matches its specific chemical composition and technological usage in metallurgy.

Identify the composition and application of Duralumin

Duralumin contains aluminium, copper, magnesium, and manganese, providing high strength and lightness for aircraft construction.

Alloying aluminium with copper and manganese enhances structural strength.

Identify the composition and application of Magnalium

Magnalium is an aluminium-magnesium alloy prized for low density and corrosion resistance in optical/scientific instruments.

Magnesium lowers density and improves machinability.

Identify the composition and application of Alnico

Alnico is composed of aluminium, nickel, cobalt, and iron, essential for permanent magnets.

The combination of ferromagnetic metals with aluminium yields high magnetic coercivity.

Identify the role of Cryolite in electrolysis

Cryolite acts as a molten solvent for alumina to reduce operating energy costs and enhance ionic conductivity.

Pure alumina melts at over

2000^\circ C

; cryolite lowers this operating temperature to around

950^\circ C

Aluminium Alloys and Extraction Metallurgy

Question