Chemistry - Copper

Introduction

• Copper is a soft, ductile, and malleable metal.

• Copper has very high thermal and electrical conductivity.

• The symbol of copper is ‘Cu’ and atomic number is ’29.’

• Copper is known to people since (about) c. 8000 BC.

• Copper is the first metal, which was smelted from its ore around c. 5000 BC.

Salient Features of Copper

• Copper was the first metal that cast into a shape (in a mold).

• Copper was the first metal that successful alloyed with another metal, e.g. copper alloyed with tin and resultantly bronze is prepared. It is done about c. 3500 BC.

• First metal to be purposefully alloyed with another metal, tin, to create bronze, c. 3500 BC.

• Copper has a natural reddish-orange color; it is visible once the its surface is exposed.

• Copper is a very good conductor of electricity and heat.

• Copper is an element of group 11 of the periodic table.

• Copper normally does not react with water; however, it does react slowly with atmospheric oxygen and form a layer of brown-black copper oxide.

• The brown-black copper oxide usually protects the underlying metal from further corrosion just like passivation.

• Passivation is a process of use of a light coat of a protective material, such as metal oxide, which is used to create a protective shell against the corrosion.

Occurrence of Copper

• Copper is commonly found in the earth’s crust.

• In 1857, the largest mass of elemental copper (weighing about 420 tones) discovered. It was found on the Keweenaw Peninsula located in Michigan, US.

Alloys of Copper

• The metal alloys, which have the copper as their major constituent, is known as copper alloys.

• Copper alloys are highly resistant to corrosion.

• The best (traditional) example of copper alloy is bronze (made by mixing tin and brass).

• Following are the major alloys of copper −

  • Brass

  • Bronze

  • Auricupride

  • Chinese silver

  • Corinthian bronze

  • Electrum, Green gold

  • Grey gold

  • Niello

  • Panchaloha

  • Rose, red, and pink gold

  • Spangold

  • Shibuichi

  • Tibetan silver

  • White gold

Compounds of Copper

• Following are the major compounds of the copper −

  • Cupric acetate - Cu(CH₃COO)₂

  • Copper(I) oxide - Cu₂O

  • Copper(II) oxide - CuO

  • Copper(II) chloride - CuCl₂

  • Dicopper chloride trihydroxide - Cu₂(OH)₃Cl

  • Copper(I) chloride - CuCl

  • Copper(II) nitrate - Cu(NO₃)₂

  • Copper Cyanide - CuCN

Uses of Copper

• Copper is largely used in making electric wires.

• Copper is used in electric motors.

• Copper is used in roofing, plumbing, and in many other industries.

• Copper paint is used in painting boats and many other materials.

• Many of the home appliances are made up of either pure copper or its alloys.