Coke and Coal Tar

Coke

• Coke is a tough, porous, and black substance that is an almost pure form of carbon.
• It is used in the manufacture of steel and in the extraction of many metals.

Coal Tar

• Coal tar is a black, thick liquid with an unpleasant smell.
• It is a mixture of about 200 substances.
• Products obtained from coal tar are used as starting materials for manufacturing various substances used in everyday life and in industry.
• Examples of these substances include synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, and roofing materials.
• Naphthalene balls used to repel moths and other insects are also obtained from coal tar.

Coal Gas

• Coal gas is obtained during the processing of coal to get coke.
• It is used as a fuel in many industries situated near the coal processing plants.
• Coal gas was used for street lighting for the first time in London in 1810 and in New York around 1820.
• Now, it is used as a source of heat rather than light.

Petroleum

• Petroleum is a natural resource from which petrol and diesel are obtained.
• The word petroleum is derived from petra (rock) and oleum (oil) as it is mined from between the rocks under the Earth.
• Petroleum is formed from organisms living in the sea that died and got covered with layers of sand and clay.
• Over millions of years, the absence of air, high temperature, and high pressure transformed the dead organisms into petroleum and natural gas.

Refining of Petroleum

• Petroleum is a dark oily liquid with an unpleasant odor.
• It is a mixture of various constituents such as petroleum gas, petrol, diesel, lubricating oil, paraffin wax, etc.
• The world’s first oil well was drilled in Pennsylvania, USA, in 1859.
• In India, oil is found in Assam, Gujarat, Mumbai High, and in the river basins of Godavari and Krishna.
• Petroleum oil and gas do not mix with water and are lighter than it, which is why the layer containing petroleum oil and gas is above that of water.