anyone help me to take the answer keys of lakhmir singh'science chemistry icse 8
Answers
1. Name three useful products of coal.
Coal tar, Coal gas, and Coke are the three useful products of coal.
2. Which product of coal is used as a reducing agent in the extraction of metals?
Coal is used as a reducing agent in the extraction of metals.
3. Name the process by which plant material (or vegetation) buried deep under the earth was slowly converted into coal.
The process by which plant material (or vegetation) buried deep under the earth was slowly converted into coal is carbonization.
4. Name the product of coal which is a thick black liquid having an unpleasant smell.
Coal is the product of coal which is a thick black liquid having an unpleasant smell.
5. Name any five substances used in everyday life that are manufactured starting from the products of coal tar.
Plastics, paints, drugs, perfumes, and paints.
6. Name an important source from which naphthalene balls are obtained.
An important source from which naphthalene balls are obtained is coal tar.
7. Which substance is used for metalling the roads these days in place of coal tar?
Bitumen is used for metalling the roads these days in place of coal tar.
8. Name the most common fuel used in light motor vehicles.
The most common type of fuel used in light motor vehicles is petrol.
9. Name the fuel which is used in jet aircraft engines.
Kerosene is used as fuel in jet aircraft engines.
10. Name the petroleum product used to drive heavy vehicles.
Diesel is used to drive heavy vehicles.
11. Name the petroleum product which is commonly used for electric generators.
The petroleum product which is commonly used for electric generators is diesel.
12. What is the full form of LPG?
Full form of LPG is Liquified Petroleum Gas.
13. Is it possible to extract petroleum from under the sea bed?
Yes, it is possible to extract petroleum from under the sea bed using a giant drilling machine.
14. What is the full form of CNG?
CNG stands for Compressed Natural Gas.
15. Name the major component of natural gas.
The major component of natural gas is Methane.
16. Name any two places in India where natural gas is found.
Maharashtra and Tripura are the two places in India where natural gas is found.
17. Name a fossil fuel other than coal and petroleum.
A fossil fuel other than coal and petroleum is natural gas.
18. Name two places in India where coal is found.
Answer
West Bengal and Jharkhand are two places in India where coal is found
19. Name the petroleum product used for surfacing of roads.
The petroleum product used for surfacing of roads is Bitumen.
20. Name any four places in India where petroleum is found.
Assam, Gujarat, Mumbai high and river basins of Godavari and Krishna are the places in India where petroleum is found.
21. Write the full form of PCRA.
PCRA stands for Petroleum Conservation Research Association.
22. State whether the following statements are true or false
(a) Coke is almost pure from carbon.
(b) Coal tar is a mixture of various substances.
(c) Kerosene is not a fossil fuel.
(d) CNG is more polluting than petrol.
(e) Fossil fuels can be made in the laboratory.
Ans:
(a) True
(b) True
(c) False
(d)False
(e) False
23. Fill in the following blanks with suitable words
(a) Fossil fuels are __________and________
(b) Coal contains mainly ___________
(c) The slow process of conversion of dead vegetation into coal is called____________
(d) The process of separation of different constituents from petroleum is____________
(e) The least polluting fuel for vehicle is ______________
(f) The burning of fossil fuel causes air _____and also causes global______
(a) Fossil fuels are coal, petroleum, and natural gas.
(b) Coal contains mainly carbon.
(c) The slow process of conversion of dead vegetation into coal is called carbonisation.
(d) The process of separation of different constituents from petroleum is refining.
(e) The least polluting fuel for vehicle is CNG
(f) The burning of fossil fuel causes air pollution and also causes global warming.
Short Answer Type Questions
24. Explain why fossil fuels are exhaustible natural resources.
The process of the formation of fossil fuels requires millions of years. Dead vegetation and animals that get buried deep inside the earth require high temperature and pressure for the formation of fossil fuels, which cannot be done in the laboratory. Thus, fossils are limited. Therefore, the use of fossil fuels at a rapid rate will lead to their exhaustion.
25. Describe how coal was formed. What is this process called?
Dense forests got buried under the soil due to natural processes, millions of years ago. More and more soil got deposited over them and they got compressed more. This led them to get exposed to very high temperature and pressure. They slowly got converted into coal under these extreme conditions. The whole process of the formation of coal from dead vegetation is known as carbonization.