Last updated on August 7th, 2023 at 04:37 pm
Coal and Petroleum Class 8 Extra Questions
Class 8 Coal and Petroleum Extra Question Answers | Class 8 Science Question Answers | for the students of cbse / icse and all board exams.
Coal and Petroleum Class 8 Extra Questions
Q: Define Inexhaustible Resources.
A: Inexhaustible resources are those that exist in unlimited quantities in nature and are unlikely to be exhausted by human activities.
Q: Define Exhaustible resources.
A: Exhaustible natural resources are those resources in nature that exist in limited quantities and can be exhausted by human activities.
Q: What is a fossil?
A: The fossils are the remains of plants or animals that were buried under the earth millions of years ago.
Q: What is fossil fuel?
A: Fossil fuels are natural fuels formed from buried remains of long-dead organisms buried deep within the earth. The dead remains of living organisms (plants and animals) buried under the earth millions of years ago produced fossil fuels.
Q: What are examples of unlimited natural resources?
A: Examples of unlimited natural resources are sunlight and air.
Q: What are examples of exhaustible natural resources?
A: Examples of exhaustible natural resources are forests, wildlife, minerals, coal, petroleum, and natural gas.
Q: What is coal and how is it formed?
A: Coal is a black and hard fossil fuel consisting mainly of carbon that was formed from the decomposition of large land plants and trees, buried under the earth about 300 million years ago. It underwent carbonisation due to high pressure and temperature.
Q: What are some uses of coal?
A: Coal is used as a fuel for cooking, in railway engines to produce steam, in thermal power plants to generate electricity, and as a fuel in various industries.
Q: What are some useful products obtained from coal?
A: Some useful products obtained from coal include coke, coal tar, and coal gas. Coke is used in the manufacture of steel and in the extraction of many metals.
Q: What is coal tar and what are some of its uses?
A: Coal tar is a black, thick liquid consisting of about 200 substances. It is used as a starting material for manufacturing various substances used in everyday life and industry, such as synthetic dyes, drugs, explosives, perfumes, plastics, paints, photographic materials, and roofing materials.
Q: What is coal gas and how is it used?
A: 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.
Q: What types of vehicles use petrol and diesel as fuel?
A: Light automobiles such as motor cycles/scooters and cars use petrol as fuel, while heavy motor vehicles such as trucks and tractors run on diesel.
Q: How is petroleum formed?
A: Petroleum is formed from the remains of 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.
Q: What is the process of separating the various constituents/fractions of petroleum called?
A: The process of separating the various constituents/fractions of petroleum is known as refining.
Q: Why is natural gas an important fossil fuel?
A: Natural gas is an important fossil fuel because it is easy to transport through pipes and can be stored under high pressure as compressed natural gas (CNG). It is also less polluting and a cleaner fuel compared to other fossil fuels.
Q: What is the great advantage of CNG and where is it used in India?
A: The great advantage of CNG is that it can be used directly for burning in homes and factories where it can be supplied through pipes. It is used for power generation and as a cleaner fuel for transport vehicles. CNG is used in some parts of Delhi, Vadodara (Gujarat), and other places in India.
Q: What are the uses of LPG?
A: Liquefied petroleum gas (LPG) is a good fuel because of its following advantages :
- LPG burns easily.
- LPG has a high calorific value. Due to this, a given amount of LPG produces a lot of heat.
- LPG burns with a smokeless flame and hence does not cause air pollution.
- LPG does not produce any poisonous gases on burning.
- LPG does not leave behind any solid residue on burning.
Q: What is CNG?
A: The majority of natural gas is composed of methane, with a small amount of ethane and propane. When natural gas is compressed by applying pressure, it is known as compressed natural gas (also known as CNG).
Q: Define Petrochemicals and their uses?
A: Chemicals that are derived from petroleum and natural gas are called petrochemicals. Petrochemicals play an important role in the production of a wide range of useful materials, such as detergents, synthetic fibers (such as polyester, nylon, acrylic), plastics (such as polyvinyl chloride, bakelite, etc.), synthetic rubber, drugs, and dyes, Fertilizers, insecticides, fertilizer, explosives, etc.
Q: Define Refining?
A: Refining is the process of separating crude petroleum oil into more useful fractions.
Chapter 4 – Materials: Metals and Non-Metals Extra Question Answers
