NCERT Solutions for Class 8 Science Chapter 3 – Coal and Petroleum (Free PDF)

NCERT Solutions for Class 8 Science Chapter 3 – Coal and Petroleum are designed to help students understand how fossil fuels like coal, petroleum, and natural gas are formed, their uses, and why they need to be conserved. This chapter explains the process of carbonization, products of coal (coke, coal tar, coal gas), refining of petroleum, and environmental concerns linked to fossil fuel usage.

By referring to these step-by-step NCERT solutions, students can easily answer textbook questions, strengthen their concepts, and prepare effectively for exams. These solutions strictly follow the CBSE guidelines, making them reliable for both class tests and final examinations. Students can also download the free PDF of NCERT Solutions Class 8 Science Chapter 3 to revise anytime and anywhere.

NCERT Class 8 Science Chapter 3 PDF Download

The NCERT Class 8 Science Chapter 3 PDF for Coal and Petroleum is available here for free download. It contains accurate and detailed answers to all textbook questions.

By downloading the Class 8 Science Chapter 3 NCERT Solutions PDF, students get:

• Step-by-step solutions for all NCERT questions.
• Notes on coal, petroleum, and natural gas.
• Diagrams of fractional distillation and carbonization.
• Answers written in exam-oriented format.
• Content available in both English and Hindi.

[Download Free PDF of Class 8 Science Chapter 3 Solutions]

For complete learning, also check:

• [NCERT Solutions Class 8 Science Chapter 2 – Microorganisms: Friend and Foe]
• [NCERT Solutions Class 8 Science Chapter 4 – Materials: Metals and Non-Metals]

Chapter Overview – Coal and Petroleum

NCERT Class 8 Science Chapter 3 – Coal and Petroleum explains about fossil fuels, their formation, uses, harmful effects, and conservation methods. Students learn how coal, petroleum, and natural gas were formed over millions of years and why they are called exhaustible resources. This chapter is important for exams as it connects science with real-life applications like electricity, transport, and industry.

What Are Fossil Fuels?

• Fossil fuels are energy-rich substances like coal, petroleum, and natural gas, formed from the remains of dead plants and animals buried under the earth for millions of years.
• They are exhaustible natural resources because they cannot be replaced quickly once used.
• Hence, fossil fuels are also known as non-renewable resources.

Formation of Coal

Coal is formed when dead plants get buried in swampy areas and, over millions of years, under high heat and pressure, change into coal. This slow process is called carbonization.

Types of coal based on carbon content:

• Anthracite – highest quality with maximum carbon.
• Bituminous – most widely used type.
• Lignite – brown coal, low quality.
• Peat – the first stage of coal formation.

Products of Coal

Coal is processed by destructive distillation to obtain useful products:

• Coke – almost pure carbon; used in steel and iron industries.
• Coal Tar – a thick black liquid containing over 200 by-products; used in paints, plastics, medicines.
• Coal Gas – used as a fuel for heating and lighting.

Formation of Petroleum and Natural Gas

• Petroleum is formed from the remains of marine plants and animals buried under sediments.
• With heat and pressure, these remains slowly changed into petroleum and natural gas.
• Petroleum is found trapped in layers of rocks, often accompanied by natural gas.

Refining of Petroleum

Petroleum is a mixture of several hydrocarbons. To make it useful, it is refined by fractional distillation in oil refineries. The important fractions obtained are:

• Petrol (Gasoline): used in cars and scooters.
• Diesel: used in buses, trucks, and trains.
• Kerosene: used in households and lamps.
• LPG (Liquefied Petroleum Gas): domestic cooking gas.
• Lubricating oil: used in machines.
• Bitumen: used for road surfacing.

Uses of Fossil Fuels

• Coal: Used to generate electricity, in steel industries, and as a domestic fuel.
• Petroleum: Used as fuel for transport, in making plastics, and other synthetic materials.
• Natural Gas: Used as domestic fuel (CNG, PNG), in fertiliser industries, and power plants.

Environmental Impact and Conservation

• Burning fossil fuels produces carbon dioxide, sulfur dioxide, and nitrogen oxides, which cause air pollution, acid rain, and global warming.
• Since fossil fuels are limited and non-renewable, conservation is very important.

Ways to conserve fossil fuels:

1. Use public transport instead of private vehicles.
2. Switch to renewable energy sources like solar, wind, and hydropower.
3. Avoid wastage of electricity and fuels at home and industries.
4. Promote energy-efficient technologies.

NCERT Exercise Questions and Answers (With Solutions)

Here are the detailed NCERT solutions Class 8 Science Chapter 3 questions and answers, written in a clear, exam-friendly format.

Fill in the Blanks

1. Fossil fuels are formed from the remains of __________.
   Answer: Plants and animals
2. The slow process of conversion of dead vegetation into coal is called __________.
   Answer: Carbonization
3. Petroleum is found in layers of rocks and is often called __________.
   Answer: Black gold
4. The destructive distillation of coal gives __________, __________, and __________.
   Answer: Coke, coal tar, coal gas
5. CNG stands for __________.
   Answer: Compressed Natural Gas

Multiple Choice Questions (MCQs)

1. Which of the following is not a fossil fuel?
   (a) Coal
   (b) Petroleum
   (c) Natural gas
   (d) Biogas
   Answer: (d) Biogas
2. Which is the cleanest fuel among the following?
   (a) Coal
   (b) Petrol
   (c) Diesel
   (d) CNG
   Answer: (d) CNG
3. Which petroleum product is used for road surfacing?
   (a) Kerosene
   (b) Diesel
   (c) Bitumen
   (d) Petrol
   Answer: (c) Bitumen
4. Which of these is not obtained by fractional distillation of petroleum?
   (a) Petrol
   (b) Coke
   (c) Diesel
   (d) Kerosene
   Answer: (b) Coke
5. Which gas is produced by incomplete combustion of coal?
   (a) Carbon dioxide
   (b) Carbon monoxide
   (c) Methane
   (d) Hydrogen
   Answer: (b) Carbon monoxide

Match the Following

1. Match Column A with Column B:

Answer:

• (i) Coke → (b) Used as fuel in steel making
• (ii) Coal tar → (c) Used in paints and medicines
• (iii) Bitumen → (a) Road surfacing
• (iv) CNG → (d) Clean fuel for vehicles

Short Answer Questions

1. What are fossil fuels?
   Answer: Fossil fuels are energy-rich substances like coal, petroleum, and natural gas formed from the remains of dead plants and animals buried under the earth millions of years ago.
2. What is destructive distillation of coal? Name its products.
   Answer: When coal is heated in the absence of air, it breaks down into useful products. This process is called destructive distillation. Its products are coke, coal tar, and coal gas.
3. Why is petroleum called black gold?
   Answer: Petroleum is called black gold because of its dark color and because it provides many valuable products like petrol, diesel, LPG, kerosene, lubricants, and bitumen.
4. What are the advantages of using CNG and LPG?
   Answer:

• They are clean fuels, producing less smoke and pollution.
• They are easy to transport and use.
• They are more efficient than coal and petrol.

Long Answer Questions

Q1. Explain the process of formation of coal.

Answer:
Coal was formed millions of years ago from the remains of dead plants that were buried in swampy areas. Over time, due to high temperature and pressure inside the earth, these remains were slowly converted into coal. This very slow process is known as carbonization.

Coal is found in different forms based on its carbon content:

• Anthracite – highest quality, hard coal with maximum carbon.
• Bituminous – most commonly used type of coal.
• Lignite – soft brown coal, low in carbon.
• Peat – the first stage of coal formation, with very little carbon.

Q2. What are the products of coal and their uses?

Answer:
Coal is processed to obtain several useful products. The main products and their uses are:

• Coke: Almost pure carbon. It is used in steel and iron industries.
• Coal Tar: A thick black liquid containing many by-products. It is used in making dyes, paints, perfumes, plastics, and medicines.
• Coal Gas: Used as a fuel for heating, cooking, and lighting.

Q3. Describe the refining of petroleum.

Answer:
Petroleum is a mixture of many hydrocarbons. It is refined by a process called fractional distillation.

In this process:

• Crude oil is heated in a distillation column.
• The vapours rise and separate into different fractions at different levels, according to their boiling points.

The main products obtained are:

• LPG (Liquefied Petroleum Gas): Cooking gas.
• Petrol: Used as fuel in cars and scooters.
• Diesel: Used in buses, trucks, and machinery.
• Kerosene: Used in stoves and lamps.
• Lubricating oil: Used in machines.
• Bitumen: Used for road surfacing.

Q4. Why is conservation of fossil fuels necessary?

Answer:
Conservation of fossil fuels is very important because they are exhaustible resources and take millions of years to form. Overuse can cause scarcity and severe environmental damage.

Conservation is necessary to:

1. Prevent air pollution and global warming caused by burning fossil fuels.
2. Ensure availability of coal, petroleum, and natural gas for future generations.
3. Encourage the use of renewable energy sources like solar, wind, and hydropower.

Q5. What are the harmful effects of burning fossil fuels?

Answer:
Burning fossil fuels has several harmful effects on health and the environment:

• Releases carbon dioxide, leading to global warming and climate change.
• Produces sulfur dioxide and nitrogen oxides, which cause acid rain.
• Emits smoke and particulate matter, leading to respiratory diseases.
• Pollutes air and contributes to climate change on a global scale.

Important Questions & Worksheets for Class 8 Science Chapter 3

Important Questions

Very Short Answer (1–2 marks)

1. Name two natural resources that are exhaustible.
2. Define fossil fuels.
3. Which gas is produced during incomplete combustion of coal?

Short Answer (3–4 marks)

1. List three products of coal and write their uses.
2. Why is petroleum called black gold?
3. Differentiate between CNG and LPG.

Long Answer (5 marks)

1. Explain the advantages and disadvantages of fossil fuels.
2. Describe the formation of petroleum.
3. Discuss why conservation of fossil fuels is necessary.

Worksheets with Answers PDF

To practice more, download the worksheet on Coal and Petroleum. These class 8 science worksheets include:

• Multiple-choice questions.
• Fill in the blanks.
• Match the following.
• Diagram-based questions.
• Higher Order Thinking Skills (HOTS).

[Download Class 8 Science Chapter 3 Worksheet with Answers PDF]

Additional Learning Resources

• Revision Notes PDF – short and quick notes on coal, petroleum, natural gas, and conservation.
• Exemplar Solutions – advanced questions for practice.
• Teacher Notes and Parent Guide – structured support for teaching and home revision.

Chapter 3, Coal and Petroleum, helps students understand the importance of fossil fuels, their formation, uses, and the urgent need for conservation. By practicing these NCERT Solutions Class 8 Science Chapter 3 questions and answers, using revision notes, and solving worksheets, students can strengthen their concepts and perform better in exams.