Coal and Petroleum chapter 5 class 8 Chemistry

5/5 - (2 votes)

Coal and Petroleum are essential topics in Class 8 Chemistry. The chapter delves into the study of coal and petroleum, two vital fossil fuels that play a significant role in our energy consumption and industrial processes.

Students will learn about the formation, composition, and properties of coal and petroleum, as well as the extraction methods used to obtain these valuable resources. By understanding the chemistry and significance of coal and petroleum, students gain insights into energy resources, their utilization, and the challenges of balancing energy needs with environmental conservation.

For your use download PDF:

Types of Resources:

Resources can be classified into three main types: natural resources, human-made resources, and human resources.

Natural resourcesHuman-made resources
Natural resources are derived from nature and include renewable resources (such as sunlight, wind, and water) and non-renewable resources (such as fossil fuels and minerals).Human-made resources are created by humans through technological processes, such as factories, machinery, buildings, and infrastructure.
Natural resources and Human-made resources
  • Human resources refer to the skills, knowledge, and abilities of individuals that contribute to economic production and development.
  • The sustainable management and utilization of all types of resources are crucial for maintaining a balanced and thriving society.

Types of Natural resources:

Renewable Resources: These are resources that can be replenished or regenerated naturally within a relatively short period of time. Examples include sunlight, wind energy, water (rivers, lakes, and groundwater), forests, and wildlife.

Non-Renewable Resources: These are resources that exist in limited quantities and cannot be replenished within a human lifetime or at a much slower rate than they are being consumed. Examples include fossil fuels (coal, petroleum, natural gas), minerals (like iron ore, copper, gold), and rocks (such as granite, limestone)

Understanding the types of natural resources helps us appreciate their significance, manage them sustainably, and make informed decisions regarding their utilization and conservation.

Energy resources and its types:

Energy resources are essential for various activities and are classified into different types. Here are three lines about energy resources and their types :

Energy resources are sources that provide the ability to do work or produce heat, powering our daily lives and driving economic development.

Inexhaustible energy resources are sources of energy that are virtually limitless and can be harnessed without the fear of depletion, such as solar and wind power.

Exhaustible energy resources are sources of energy that are finite in quantity and can be depleted over time, such as fossil fuels.

Formation of fossil fuels:

  • Fossil fuels are formed through a process that takes millions of years, starting with the accumulation of organic matter from ancient plants and animals.
  • As plants and organisms die, their remains sink into layers of sediment, such as mud or sand, at the bottom of oceans, lakes, or swamps.
  • Over time, the organic matter becomes buried under more layers of sediment, subjecting it to high pressure and temperature, a process known as compaction and heat.
  • The heat and pressure transform the organic matter into hydrocarbons, the primary components of fossil fuels.
  • Depending on the specific conditions during formation, different types of fossil fuels are produced, such as coal from plant remains, petroleum from marine organisms, and natural gas from the decomposition of organic matter.

Carbonisation is the process of converting organic matter, such as plant material, into coal through high pressure, heat, and the removal of volatile components, while coal mining involves extracting coal deposits from the Earth’s surface or underground for energy production.

Formation of Petroleum and Natural Gas:

Petroleum is formed from the remains of marine organisms, such as microscopic plants and animals, which undergo heat and pressure over millions of years, while natural gas is formed alongside petroleum through similar processes, but typically in areas with higher temperatures and under specific geological conditions.

Uses of coal:

Coal, a fossil fuel, has multiple uses, including electricity generation, industrial processes, heating, and steel production.

The primary types of coal are anthracite, bituminous, sub-bituminous, and lignite, classified based on their carbon content and energy value.

Anthracite coal is the highest grade and has the highest carbon content, making it suitable for heating and steelmaking.

Coal can be processed to obtain various valuable products. Here are some of the main products derived from coal:

CokeCoal is heated in the absence of air to produce coke, a porous carbon-rich material.
Coke is primarily used in the production of iron and steel as a fuel and reducing agent.

Coal GasBy heating coal in the absence of air, coal gas is produced. It is a mixture of gases, including methane, carbon monoxide, hydrogen, and small amounts of other gases.
Coal gas has been historically used for heating, lighting, and fueling certain industrial processes.

Coal TarThrough the process of destructive distillation, coal tar is obtained. It is a thick, black liquid with a complex mixture of organic compounds.
Coal tar finds applications in various industries, including the production of roofing materials, dyes, pesticides, and pharmaceuticals.

Products Obtained from coal


  • Petroleum, also known as crude oil, is a naturally occurring fossil fuel formed from the remains of ancient marine organisms, primarily microscopic plants and animals.
  • It is a complex mixture of hydrocarbons, consisting of different carbon and hydrogen compounds, along with trace amounts of impurities such as sulfur, nitrogen, and oxygen.
  • Petroleum is a crucial energy resource and serves as a raw material for the production of various products, including gasoline, diesel fuel, jet fuel, heating oil, lubricants, plastics, synthetic fibers, and many other everyday items.
Diagram showing fractional distillation crude oil:
Diagram showing fractional distillation crude oil illustration

An Uncertain Future:

  1. The future of coal and petroleum faces uncertainty as concerns over environmental impacts and climate change continue to grow.
  2. Increasing efforts to transition towards cleaner and more sustainable energy sources pose challenges to the long-term viability of coal and petroleum industries.
  3. Technological advancements and shifting global energy policies are likely to influence the demand for coal and petroleum, leading to an uncertain future for these fossil fuels.
  4. Class 8 students studying coal and petroleum are encouraged to explore alternative energy solutions and understand the importance of environmental sustainability in shaping the energy landscape of tomorrow.

Most asked questions of class 8 coal and petroleum

1.Write the names of two natural substances.

Ans: Water and air are two natural substances.

2. What is the purest form of carbon?

Ans: The purest form of carbon is diamond.

3. What is the main use of coke?

Ans: The main use of coke is in the production of iron and steel.

4. Name two fractions of petroleum.

Ans: Two fractions of petroleum are gasoline (petrol) and diesel.

5. What are natural resources? Explain with examples.

Ans: Natural resources are substances or materials that exist in nature and are used by humans for various purposes. Examples include forests, minerals, water bodies, and sunlight..

Leave a Comment