Solution:

Advantages of Using CNG and LPG as Fuels

CNG (Compressed Natural Gas):

• Environmentally friendly: CNG produces fewer pollutants like carbon dioxide (CO2), nitrogen oxides (NOx), and particulate matter compared to petrol or diesel, making it a cleaner fuel.
• Cost-effective: CNG is generally cheaper than petrol and diesel, which helps reduce the cost of transportation and energy consumption.
• Efficient combustion: CNG burns more efficiently, providing better fuel economy and less wear and tear on engines.
• Non-toxic: CNG is non-toxic and safe to handle, reducing health risks associated with other fuels.
• Reduced greenhouse gas emissions: CNG produces fewer greenhouse gases, helping to reduce global warming and climate change.

LPG (Liquefied Petroleum Gas):

• Cleaner combustion: LPG burns more cleanly than coal, petrol, and diesel, leading to lower emissions of harmful substances like CO2 and smoke.
• High calorific value: LPG has a higher calorific value, which means it provides more energy per unit compared to other fuels.
• Portable and convenient: LPG is easy to store and transport in cylinders, making it ideal for cooking and heating in homes and industries.
• Less harmful to the environment: LPG causes less pollution and is a more sustainable alternative to other fossil fuels.
• Safer than petrol or diesel: LPG is safer to handle because it is stored as a liquid under pressure, and in the event of leakage, it disperses quickly, reducing fire hazards.

Solution:

Petroleum product used for surfacing of roads

The petroleum product used for surfacing of roads is Bitumen.

Solution:

Formation of Coal from Dead Vegetation

Coal is formed from the remains of dead plants and vegetation that accumulated in swampy or marshy areas millions of years ago. The process involves several stages:

1. Accumulation of Plant Material: Dead plants and trees accumulate in swampy or low-lying areas. These areas have little oxygen, so the decaying process is slow.
2. Peat Formation: Over time, the accumulated plant material gets buried by layers of mud and water, preventing complete decay. The partially decomposed plant material turns into a substance called peat.
3. Formation of Lignite: As more layers of plant material and mud build up over time, the pressure and heat increase, transforming peat into lignite, a soft, brownish coal.
4. Formation of Bituminous Coal: With further pressure and heat, lignite changes into bituminous coal, which is a harder, black coal used for energy production.
5. Formation of Anthracite: After millions of years, under even greater pressure and heat, bituminous coal can transform into anthracite, the hardest and most carbon-rich form of coal.

This entire process, over millions of years, is called coalification.

Solution:

(a) Fossil fuels are _______ , _________ and _______ .

Answer: coal, petroleum, natural gas

(b) Process of separation of different constituents from petroleum is called __________.

Answer: refining

(c) Least polluting fuel for vehicle is __________.

Answer: CNG (Compressed Natural Gas)

Solution:

Tick True or False against the following statements:

• (a) Fossil fuel can be made in the laboratory. - False
• (b) CNG is more polluting fuel than petrol. - False
• (c) Coke is almost pure form of carbon. - True
• (d) Coal tar is a mixture of various substances. - True
• (e) Kerosene is not a fossil fuel. - False

Solution:

Why Fossil Fuels are Exhaustible Natural Resources

Fossil fuels, such as coal, petroleum, and natural gas, are considered exhaustible natural resources because they are formed over millions of years from the remains of plants and animals. This process takes a long time, and the rate at which fossil fuels are being consumed today is much faster than the rate at which they are being formed. As a result, once these fuels are depleted, they cannot be replenished within a human timescale.

The formation of fossil fuels involves complex geological processes. Organic matter, buried under layers of soil and rock, undergoes heat and pressure over millions of years. This results in the conversion of the organic material into coal, oil, or gas. However, these resources are finite, and once used up, there will be no immediate way to create more. Therefore, fossil fuels are classified as non-renewable resources.

Additionally, the extraction of fossil fuels leads to environmental degradation, which can further limit their availability. The excessive use of fossil fuels also contributes to global warming and climate change, which poses a threat to the future availability of these resources.

Solution:

Characteristics of Coke

Coke is a solid carbon-rich material derived from the destructive distillation of coal in the absence of air. The process is called coking. It has the following characteristics:

• Coke is a hard, porous, and black substance.
• It contains about 90-95% carbon.
• Coke has a high heating value, making it an excellent fuel.
• It is almost free from impurities like sulfur and phosphorus.
• Coke burns with a luminous flame, releasing a lot of heat.
• It is used in the production of iron and steel in blast furnaces.

Uses of Coke

Coke has several important uses, especially in the industrial sector:

• Fuel: Coke is primarily used as a fuel in the production of heat and power in various industries.
• In Blast Furnaces: Coke is used as a reducing agent in the extraction of metals, especially iron. It reacts with iron ore (Fe2O3) to produce molten iron.
• In the Production of Steel: Coke is used in steel-making furnaces, where it provides both the necessary heat and a source of carbon for making steel from iron.
• In the Chemical Industry: Coke is used as a raw material in the production of various chemicals such as acetic acid, methanol, and other industrial solvents.
• In Gas Production: Coke can be gasified to produce coal gas, which is used as a fuel in lighting, heating, and cooking.

Solution:

Process of Formation of Petroleum

Petrroleum is formed from the remains of ancient marine organisms, such as plankton, that lived millions of years ago. The process involves several stages:

1. Deposition of Organic Material: The remains of dead plants and animals settle on the ocean floor. Over time, they get mixed with mud and sand.
2. Formation of Sedimentary Layers: The accumulated organic material gets buried under layers of sediments. The weight of these layers increases with time.
3. Transformation into Kerogen: As the layers of sediment become thicker, pressure and temperature increase. The organic matter slowly changes into a substance called kerogen, which is a precursor to petroleum.
4. Conversion to Oil and Gas: As the temperature and pressure continue to rise, kerogen undergoes chemical changes and transforms into liquid hydrocarbons (petroleum) and natural gas.
5. Migration of Petroleum: The petroleum then moves upwards through porous rocks due to its lighter density. It gets trapped in impermeable rocks, forming oil reservoirs.

Solution:

Power Shortage in India (1991-1997)