Olympiad Test: Coal And Petroleum - 1 - Free MCQ with solutions Class 8

Non-renewable resources, such as coal, petroleum, and natural gas, are formed over millions of years and cannot be replenished quickly. They are being used up much faster than they are formed, which means they are slowly getting exhausted. If we continue to overuse them, these resources will eventually run out, as nature cannot replace them within a human lifetime. Therefore, all of the reasons listed contribute to the need for conserving non-renewable resources, making 'all of these' the correct answer.

Explanation:
The given question asks for an important fraction of petroleum that is further distilled to obtain lubricating oil and paraffin wax. To answer this question, we need to understand the process of petroleum refining and the various fractions it yields.
1. Petroleum: Petroleum, also known as crude oil, is a naturally occurring fossil fuel found beneath the Earth's surface. It is a mixture of hydrocarbons, which are organic compounds made up of hydrogen and carbon atoms.
2. Distillation: Petroleum refining involves the process of distillation, which separates the various components of crude oil based on their boiling points. Distillation occurs in a series of steps or stages.
3. Residue: During the distillation process, the heaviest and highest boiling point fraction of crude oil is obtained. This fraction is known as residue. It contains high molecular weight hydrocarbons and impurities.
4. Lubricating Oil: The residue fraction obtained from petroleum distillation is further processed to obtain lubricating oil. Lubricating oil is a thick liquid that is used to reduce friction between moving parts, such as in engines and machinery.
5. Paraffin Wax: Paraffin wax is another product obtained from the residue fraction of petroleum. It is a white, solid substance that is commonly used in candles, cosmetics, and other applications.
Therefore, the correct answer is D: residue. The residue fraction of petroleum is an important component that is further distilled to obtain lubricating oil and paraffin wax.

Not a renewable resource:
- Petroleum
Renewable resources:
- Air: Air is a renewable resource because it is constantly being replenished through natural processes such as photosynthesis and the water cycle.
- Sunlight: Sunlight is a renewable resource as it is produced by the sun and is available in abundance. It can be harnessed through solar panels and converted into electricity.
- Water: Water is also a renewable resource as it is constantly being recycled through the water cycle. It can be used for various purposes such as drinking, irrigation, and hydropower generation.
Explanation:
- Petroleum, also known as oil, is a fossil fuel that is derived from ancient organic materials such as plants and animals. It is not considered a renewable resource because it takes millions of years for the earth to produce new reserves of oil. Once extracted and consumed, petroleum cannot be easily replaced within a human lifespan. It is a finite resource that will eventually run out if not managed properly.
In conclusion:
- While air, sunlight, and water are renewable resources that can be replenished naturally, petroleum is a non-renewable resource that is limited in supply. It is important to conserve and explore alternative energy sources to reduce our dependence on fossil fuels like petroleum.

Destructive distillation of coal produces:
- Coal gas: Destructive distillation of coal involves heating coal in the absence of air, which leads to the production of coal gas. This gas is a mixture of various gases, including methane, hydrogen, carbon monoxide, and carbon dioxide.
- Tar: Another product of destructive distillation is tar, which is a thick, black, sticky substance. Tar has various industrial applications, such as in road construction and waterproofing.
- Ammonia: Destructive distillation of coal also produces ammonia gas. Ammonia has numerous uses, including as a fertilizer, refrigerant, and in the production of various chemicals.
- Coke: The residue left behind after destructive distillation of coal is coke. Coke is a solid carbonaceous material that is used as a fuel and in the production of iron and steel.
- Other byproducts: The process of destructive distillation also yields other byproducts such as benzene, toluene, and naphthalene, which have various industrial applications.
It is important to note that the specific composition and quantities of the products obtained from destructive distillation of coal can vary depending on the type of coal used and the specific conditions of the distillation process.

Explanation:
The best quality of coal is anthracite. Here is a detailed explanation:
Types of Coal:
1. Peat: It is the lowest rank of coal and is partially decayed vegetation. It has the highest moisture content and the lowest carbon content. Peat is not considered a good quality coal.
2. Lignite: It is a brownish-black coal with a high moisture content and low carbon content. Lignite is often referred to as brown coal and is commonly used for electricity generation.
3. Bituminous: This type of coal is black and relatively soft. It has a higher carbon content compared to lignite and is widely used in electricity generation and industrial processes.
4. Anthracite: Anthracite is the highest rank of coal and has the highest carbon content. It is hard, shiny, and dense. Anthracite has a low moisture content and burns with a clean flame and little smoke. Due to its high carbon content, it has a high energy density and is considered the best quality of coal.
Conclusion:
The best quality of coal is anthracite, which has a high carbon content and low moisture content. It is hard, dense, and burns with a clean flame. Anthracite is widely used for various purposes, including electricity generation and industrial processes.

Non-polluting fuel for vehicles:
D: CNG (Compressed Natural Gas)
- CNG is considered a non-polluting fuel for vehicles because it produces significantly fewer harmful emissions compared to traditional fossil fuels like petrol, diesel, and kerosene.
- It is composed mostly of methane gas, a hydrocarbon that burns cleaner than other fossil fuels.
- When CNG is used as a fuel, it releases lower levels of carbon monoxide, nitrogen oxides, and particulate matter.
- CNG also produces fewer greenhouse gas emissions, such as carbon dioxide, which contribute to climate change.
- The combustion of CNG is more efficient, resulting in better fuel economy and reduced fuel consumption.
- CNG is a versatile fuel that can be used in a wide range of vehicles, including cars, buses, taxis, and trucks.
- It is considered a safer fuel option compared to petrol and diesel because it is lighter than air and disperses quickly in the event of a leak.
- CNG fueling infrastructure is expanding globally, making it more accessible for vehicle owners to switch to this cleaner fuel option.
In conclusion, CNG is a non-polluting fuel for vehicles that offers several environmental and efficiency advantages over traditional fossil fuels like petrol, diesel, and kerosene.

The energy contained in fuels that is locked within the chemical bonds of their constituent molecules is potential energy.
Potential energy is the energy stored within an object or substance due to its position or state. In the case of fuels, potential energy is stored within the chemical bonds of the molecules that make up the fuel. When these bonds are broken, the potential energy is released and can be converted into other forms of energy such as kinetic energy, heat energy, or light energy.
Here's a breakdown of the options:
A: Potential energy:
- Potential energy is the stored energy within an object or substance.
- In the case of fuels, the potential energy is stored within the chemical bonds of the fuel molecules.
- When these bonds are broken, the potential energy is released and can be used to do work or produce other forms of energy.
B: Kinetic energy:
- Kinetic energy is the energy of motion.
- While the combustion of fuels does release kinetic energy, it is not the energy that is stored within the chemical bonds of the fuel molecules.
C: Heat energy:
- Heat energy is a form of energy that is transferred between objects due to a temperature difference.
- The combustion of fuels does release heat energy, but this is a result of the potential energy within the chemical bonds being converted into thermal energy.
D: Light energy:
- Light energy is a form of electromagnetic radiation that can be produced through various processes, such as combustion.
- While the combustion of fuels can produce light energy, it is not the energy that is stored within the chemical bonds of the fuel molecules.
In conclusion, the energy contained in fuels that is locked within the chemical bonds of their constituent molecules is potential energy.

Fossil Fuels:
Fossil fuels are natural resources that are formed over millions of years from the remains of ancient plants and organisms. They are non-renewable sources of energy and play a significant role in meeting the world's energy demands. The main types of fossil fuels include coal, petroleum, and natural gas.
Coal:
- Coal is a black or brownish-black sedimentary rock that is primarily composed of carbon, along with various other elements such as hydrogen, sulfur, oxygen, and nitrogen.
- It is formed from the remains of plants that lived and died millions of years ago.
- Coal is extracted through mining and is used primarily as a fuel for electricity generation and industrial processes.
Petroleum:
- Petroleum, also known as crude oil, is a thick, dark liquid that is found beneath the Earth's surface.
- It is formed from the remains of marine organisms that were buried and subjected to high pressure and heat over millions of years.
- Petroleum is a vital energy source and is refined into various products such as gasoline, diesel, jet fuel, and lubricants.
Natural Gas:
- Natural gas is a mixture of hydrocarbon gases, primarily composed of methane.
- It is formed in similar geological processes as petroleum and is often found alongside petroleum deposits.
- Natural gas is used for heating, cooking, electricity generation, and as a raw material in the production of various chemicals.
All of these:
- Fossil fuels, including coal, petroleum, and natural gas, are all examples of non-renewable energy sources that are derived from ancient organic material.
- They are widely used for various purposes and are major contributors to global energy consumption.
- However, the combustion of fossil fuels releases carbon dioxide and other greenhouse gases, contributing to climate change and environmental degradation.
- Therefore, there is a growing need to transition towards renewable and sustainable sources of energy to reduce our dependence on fossil fuels.