GSEB Solutions for Class 8 Science and Technology – Fossil Fuels

GSEB Solutions for Class 8 Science and Technology – Fossil Fuels (English Medium)

GSEB SolutionsMathsScience
Exercise 66:

Solution 1(a):

1. Petroleum: Vehicles like car, truck, trains, ships and aircraft run by using some sort of petroleum. Plastic and oil based paints, as well as paint additives, are manufactured from petroleum products. Lubricants for machines and skin cream (vasoline), some household product and even make-up items have petroleum based products.
2. Kerosene: kerosene is used in cooking, lighting, and heating. It has also been used as a pesticide where it is poured on still water to deter and kill mosquitoes. Kerosene is also used as a motor fuel for tractors and generators. Kerosene is often used in the entertainment industry for fire performances.
3. C.N.G: Compressed natural gas is used in steam heat production, electrical generation. It is useful in day to day life for cooking, heating, fuel for transportation etc. It is also useful in industries like producing steel, glass etc.

Exercise 69:

Solution 1(a):

Petroleum gas is obtained at the uppermost part of the fractional distillation tower.

Solution 1(b):

Petroleum gas is obtained at 25°C.

Solution 1(c):

Petrol gets separated between 30°C and 120°C.

Solution 1(d):

Diesel gets separated at 260°C.

Solution 1(e):

Coal tar.

Exercise 70:

Solution 1(a):

Carbon dioxide, carbon monoxide, nitrogen oxide are the gases that exist in the smoke of the exhaust of the vehicles; due to which, the proportion of pollution has increased.

Exercise 71:

Solution 1(a):

Advantages of petroleum:

1. Storage and transportation systems are simple.
2. Petroleum fuels are quite clean.
3. Certain components make excellent solvents for paint, industrial use etc.
4. It has high energy density.

Disadvantages of petroleum:

1. Excess use of petroleum creates local and global problems.
2. It is limited resource and costly.
3. Process of refining creates toxic waste products.
4. Oil spills, especially at sea, can damage ecosystems.

Solution 1.1:

There are three types of fossil fuels which are as follows:

1. Mineral coal
2. Petroleum (Mineral oil)
3. Natural gas

Solution 1.2:

There are four types of mineral coal as follows:

1. Peat coal
2. Lignite
3. Bitumen
4. Anthracite

Solution 1.3:

By fractional distillation, the following substances are obtained:
Petroleum gas, Petrol, Naphtha, Kerosene, Diesel, Lubricating oil, Fuel oil and Coal tar.

Solution 1.4:

It is used in vehicles and as a fuel for cooking food.

Solution 1.5:

Lignite is used in thermal power stations and railways.

Solution 2.1:

If we make extravagant use of petrol, diesel, there is a probability that it will be exhausted in the future. Due to this, we must use substances like petrol, diesel sparingly and judiciously.

Solution 2.2:

We can use petrol, diesel judiciously in the following ways:

1. Drive at constant and moderate speed as much as possible.
2. Switch off the engine at traffic lights.
3. Ensure correct tyre pressure.
4. Ensure regular maintenance of vehicle.

Solution 3.1:

True.

Solution 3.2:

True.

Solution 3.3:

False. It is used as motor oil and also to prepare grease.

Solution 3.4:

True.