Uses of Metals: Aluminum & Copper

Dr. Mudassar Altaf, Associate Professor of Chemistry, Department of Higher Education, Government of the Punjab, Pakistan

Contents:

• Use of aluminum
• Use of copper

Uses of Aluminum:

• Aluminum is the metal that can be used as a sheet to build structures, like windows, doors, and even aeroplane bodies. Although, zinc and iron are also used for the same purposes. But for aeroplane bodies, aluminum is the best selection due to its lower density (2.70 g/cm³) as compared to zinc (7.14 g/cm³) and iron (7.87 g/cm³). So, zinc and iron are not as light weight as the aluminum.

• Further, silver, platinum and gold are very expensive metals. The aluminum is not as expensive as these are. So, it is a better choice for constructing aeroplane bodies.
• The aluminum is not used in its pure form in making aeroplane bodies; but predominantly in the form of alloy to provide extra strength. Otherwise, due to relatively a soft metal, its use in heavy-duty construction of aeroplane bodies is not suitable. For example, aluminum-copper alloy, where more than 90% is aluminum, more than 3% is copper, and few other metals are also used in fractions, like Mg, Mn, Zn, Fe, Cr etc. to give the alloy an extra strength, and to make it corrosion-free.

• Because of low density, the aluminium is also used as overhead electrical cables run as power lines on electric poles along the roads. These are high-voltage transmission lines due to good electrical conductivity.

Fascinating Information:

From dam or power station, the voltage of electricity has to pass through various step-up and step-down transmissions; and the overhead aluminum cables transmit the electricity. Following is a flow-chart given just to have an idea.

• Aluminium foil is used for preserving food. It is used in the form of foil to wrap food, as foil container, or tin cans. Aluminum is a recycling material. Mostly, tin cans are made from recycled aluminum. Further, aluminum is free of corrosion due to formation of a protective covering of aluminum oxide. Safety Measures: It is necessary that very hot food, vinegar or lemon juice containing food for a longer time shouldn’t be wrapped with aluminum; otherwise, it can migrate into the food. The healthy kidneys have a capacity to remove absorbed aluminum. However, a person having weaker kidneys should avoid.

Uses of Copper:

• The electric current can flow easily through copper with low resistance due to higher electrical conductivity of the metal. It is also used in wiring of electric circuits at home. 
• It is ductile and can be drawn into wires easily without breaking. So, copper is also used widely in winding motors of fans, washing machines, water pumps etc.