NCERT Exemplar Solution for Class 8 Science Chapter-5- Coal and Petroleum
Coal and petroleum are among the most important natural resources discussed in middle school science because they play a major role in transportation, electricity generation, industries, and daily life. This chapter explains how these fossil fuels were formed over millions of years from dead plants and animals buried deep inside the Earth. It also highlights the importance of conserving natural resources and using fuels wisely to protect the environment. The NCERT Exemplar Solution for Class 8 helps students understand concepts such as carbonisation, natural gas, refining of petroleum, and the harmful effects of excessive fuel consumption. Students preparing with the NCERT Exemplar Solution can strengthen their scientific understanding and improve problem-solving skills for exams. The chapter is also very useful for learning practical applications of science in everyday life through reliable NCERT solutions for class 8.
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Formation and Uses of Coal and Petroleum
Coal is a hard, black substance mainly composed of carbon. It was formed from the remains of huge forests buried under the Earth millions of years ago. Due to high temperature and pressure inside the Earth, dead vegetation slowly converted into coal. This slow process is known as carbonisation. Coal is widely used as a fuel in thermal power plants and industries. It is also used to produce coke, coal tar, and coal gas.
Petroleum, on the other hand, is a dark oily liquid often called black gold because of its high commercial value. It was formed from the remains of tiny marine organisms buried under layers of sand and clay. Petroleum is extracted through oil wells and sent to refineries where it is separated into different useful products. These products include petrol, diesel, kerosene, lubricating oil, paraffin wax, and bitumen. Natural gas is another important fossil fuel found along with petroleum deposits. It is considered a cleaner fuel because it produces less smoke and harmful gases compared to coal and petrol. Compressed Natural Gas (CNG) is commonly used in vehicles and homes for cooking.
The NCERT Exemplar Solution for Class 8 explains these concepts through application-based questions and examples that improve scientific thinking among students.
Petroleum Refining and Important Products
Petroleum obtained from the Earth cannot be used directly because it contains several impurities and different substances mixed together. In petroleum refineries, crude oil is separated into different fractions based on their boiling points. This process is known as refining.
Each fraction of petroleum has different uses in daily life. Petroleum gas is used as LPG for cooking. Petrol is commonly used as fuel in motorcycles and cars. Diesel powers buses, trucks, and generators. Kerosene is often used in stoves and lamps. Lubricating oil helps machines work smoothly by reducing friction. Paraffin wax is used in candles, ointments, and cosmetics, while bitumen is used for constructing roads. The chapter also discusses how fossil fuels are limited natural resources. Since coal and petroleum take millions of years to form, they cannot be replaced quickly once exhausted. This is why they are called exhaustible natural resources.
Through the NCERT Exemplar Solution, students learn the importance of careful fuel usage and the need for alternative energy resources like solar energy, wind energy, and biogas.
Conservation of Fossil Fuels and Environmental Impact
Excessive use of fossil fuels creates environmental problems such as air pollution, acid rain, and global warming. Burning coal and petroleum releases carbon dioxide, sulphur dioxide, and other harmful gases into the atmosphere. These gases increase pollution levels and affect human health as well as the environment. Conservation of fossil fuels is therefore extremely important. Simple habits like switching off vehicle engines at traffic signals, using public transport, carpooling, and saving electricity can reduce fuel consumption. People are also encouraged to use cleaner fuels such as CNG and LPG.
The chapter creates awareness about sustainable development and responsible use of resources. Students also learn that scientific advancement should be balanced with environmental protection. Questions included in the NCERT Exemplar Solution for Class 8 help learners connect textbook knowledge with real-world environmental concerns. By practising exemplar questions, students become more confident in answering conceptual and reasoning-based questions. These solutions also help improve understanding of scientific terms and processes in a simple and structured way.
Importance of Studying Coal and Petroleum
This chapter is important because it teaches students about energy resources that directly affect human life and industrial development. It also encourages awareness regarding conservation and environmental protection. Understanding the formation, uses, and limitations of fossil fuels helps students appreciate the need for renewable energy sources.
The NCERT solutions for class 8 provide detailed explanations for every important topic in the chapter. Students can revise concepts like carbonisation, refining, natural gas, and fuel conservation more effectively through exemplar-based practice. Regular study of these solutions helps improve accuracy, analytical ability, and exam preparation.