General Properties and Production of Metals

General Properties

Metals: lustrous, malleable, and good conductors of electricity and heat.

The lightest metal: Li, the heaviest Os, the liquid one Hg, the best electrical conductor Ag, the hardest Cr.

Electrochemical Series

Chemical activity is assessed using the electrochemical series. Activity decreases from left to right.

Li K Ba Ca Na Mg Al Mn Zn Cr Fe Ni Sn Pb (H) Cu Hg Ag Pt Au

1	2	3	4	5
Li	K	Ca	Na	Mg
Al	Zn	Fe	Pb	H
Cu	Ag	Au

• Only metals to the left of hydrogen displace H₂. They displace hydrogen from acids.
• Each metal displaces the metal to its right from a solution of its salt (except for active metals that react with water).

Methods of Production

• Pyrometallurgy: reduction with C, CO, H₂, Al at high temperature.
• Hydrometallurgy: displacement from a solution.
• Electrometallurgy: electrolysis.
• K, Na, Ca, Al: mainly by electrolysis (of the melt).

Examples:

• Fe₂O₃ + 3CO → 2Fe + 3CO₂ (blast furnace).
• Cr₂O₃ + 2Al → Al₂O₃ + 2Cr (aluminothermy).

Alloys and Corrosion

• Steel: Fe + C (less than 2%).
• Cast iron: C more than 2%.
• Bronze: Cu + Sn.
• Brass: Cu + Zn.
• Duralumin: Al, Cu, Mg.
• Corrosion: the destruction of metals under the influence of their environment. Protection: painting, coating, sacrificial anode (protector).