Aluminium
Aluminium
Symbol : Al,
Atomic Number — 12,
Mass Number — 24
Physical and Chemical Properties :
Aluminium doesn’t occur in nature in free state but occurs in the forms of compounds like bauxite (A12O2.2H2O), Corundum (A12O3), Diaspore (A12O3.H20). Al is a white glazing metal like silver. This is a good conductor of heat and electricity, and it is malleable and ductile.
» Its melting point and boiling point are 659.8°C and 2,200°C
Uses :
This metal (aluminium) and its alloys are frequently used in aircrafts, motor vehicle industries. The cooking utensils are manufactured by the alloys of it and by the metal itself.
| Alloys | Composition |
|---|---|
| Aluminium bronze | Al + Cu |
| Magnelium | Al + Mg + Cu + Fe |
| Nickelloy | Al + Ni + Cu |
| Duralium | Mn + Mg |
Compounds of Aluminium
Aluminium Chloride (AlC13) :
This is used as a catalyst in Friedel Craft reaction which occurs on an extensive level. This is also used as a catalyst in the production of Gasoline. It is also used in cracking of petroleum anhydrous A1C13.
Potash Alum [K2SO4.A1(SO4)3.24H2O] :
This is a double salt that appears as a colourless crystalline solid. This is also used in pulp-paper and leather industries, as an antiseptic and as a germicide after shaving, as a germicide for purification of water, etc.
Aluminium Hydroxide [Al(OH)3] :
This is a white amorphous powder insoluble in water, and it is a covalent compound. This is used in making fire proof and water proof clothes; in the name of aluminium gel, it is used as a drying agent, freshly precipitated A1(OH)3 absorbs colouring matter forming insoluble lakes.