Coal and petroleum Worksheet-6

Coal and petroleum Worksheet-6

1. Name any six amorphous forms of carbon and also their method of preparation.

2. What is LPG? Mention its main component. Why is a smelling agent added to it?

3. Explain the process of formation of petroleum? Name two places in India where it is found.

4. Why are coal and petroleum known as fossil fuels?

5. Give two characteristics of coal.

6. Define destructive distillation. Name the residue formed by destructive distillation of coal.

7. What are the uses of coke?

8. What is meant by refining of petroleum and where is it done?

9. Name the substance obtained for petroleum refining which is used for manufacturing fibres, plastics.

10. How can bitumen be used?

Answer:

1. The amorphous forms of carbon are:

Coal

 It is formed by carbonization of wood. Anthracite is the purest form of coal it contains 94 – 95% of carbon.

Wood Charcoal

Charcoal is a black, porous and brittle solid obtained when wood is heated strongly in a very limited supply of air. This process is called destructive distillation of wood. It is a good adsorbent. Charcoal powder adsorbs colouring matter from solutions, and poisonous gases from the air

Animal Charcoal

Animal charcoal (or Bone charcoal) is obtained by destructive distillation of bones. It contains about 10-12% of amorphous carbon.

Sugar Charcoal

It is obtained by heating sugar in the absence of air. Sugar charcoal is the purest form of amorphous carbon.

Lamp Black

Lamp black is manufactured when tar and vegetable oils (rich in carbon) are burnt in an insufficient supply of air and the resulting soot is deposited on wet blankets hung in a room. Lamp black is a velvety black powder. It is used in the manufacture of India ink, printer's ink, black paint and varnishes and carbon papers.

Carbon Black

When natural gas is burned in limited supply of air, the resulting soot is deposited on the underside of a revolving disc. This carbon black is then scraped off and filled in bags. It differs from lamp black in being not so greasy. Carbon black is added to the rubber mix used for making automobile tyres, and has replaced the use of lampblack for a number of purposes.

2. LPG is abbreviation for liquid petroleum gas. It is a non-renewable source of energy.  The main composition of LPG is hydrocarbons containing three or four carbon atoms.

The normal components of LPG thus, are propane (C₃H₈) and butane (C₄H₁₀).  

The gas is stored in liquid form under pressure in a steel container, cylinder or tank

A foul smelling mercaptan is added to LPG as it is colourless, odourless gas so that leaking can be easily detected.

Formation of Petroleum and natural gas

Petroleum was formed from organisms living in the sea. As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay.

Over millions of years, absence of air, high temperature and high pressure transformed the dead organisms into petroleum and natural gas.

4. Coal and Petroleum were formed from the dead remains of living organisms (fossils).

So, these are known as fossil fuels.

5. Coal is a combustible sedimentary rock composed mostly of carbon and hydrocarbons. It is a nonrenewable resource. It is black or brownish-black in colour.

Coal burns producing large amount of energy.

Coal is used for manufacturing coke which is used in the manufacture of steel.

6. The process of heating coal in the absence of air is called destructive distillation of coal.

The main products formed are:

coke

coal tar

coal gas

7. Coke is used as a domestic fuel.

Coke is used in the manufacture of steel

Coke is used in the extraction of iron from its ore.

8. Petroleum or crude oil is a complex mixture of solid, liquid, and gaseous hydrocarbons.

Refining is done to separate useful substances from petroleum. It is done by fractional distillation in oil refineries.

9. Petrochemicals obtained from refining of petroleum /crude oil is used in the manufacture

of detergents, fibres (polyester, nylon, acrylic etc.), polythene and other man-made plastics.

10. Bitumen is a petroleum product used for surfacing roads.