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Nature's Treasures - Fossil Fuels

Grade 6CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Fossil fuels are natural resources formed from the remains of dead plants and animals buried deep under the earth millions of years ago, such as coal, petroleum, and natural gas.

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Carbonization is the slow chemical process by which dead vegetation buried under high temperature and high pressure is converted into coal, primarily consisting of Carbon (CC).

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Coal products include Coke (purest form of carbon), Coal Tar (used in perfumes and dyes), and Coal Gas (used for industrial heating).

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Petroleum, often called 'Black Gold', is a dark oily liquid refined through fractional distillation to produce petrol, diesel, kerosene, and paraffin wax.

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Natural Gas is a very important fossil fuel because it is easy to transport through pipes and is stored under high pressure as Compressed Natural Gas (CNGCNG).

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Fossil fuels are non-renewable or exhaustible resources because their formation takes millions of years, and current consumption rates far exceed their rate of formation.

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Burning fossil fuels releases pollutants like Carbon dioxide (CO2CO_2), which contributes to global warming and the greenhouse effect.

📐Formulae

Methane (Main component of Natural Gas)=CH4\text{Methane (Main component of Natural Gas)} = CH_{4}

Combustion of Carbon: C+O2→CO2+Heat\text{Combustion of Carbon: } C + O_{2} \rightarrow CO_{2} + \text{Heat}

Combustion of Methane: CH4+2O2→CO2+2H2O+Energy\text{Combustion of Methane: } CH_{4} + 2O_{2} \rightarrow CO_{2} + 2H_{2}O + \text{Energy}

Efficiency=Useful Energy OutputTotal Energy Input×100%\text{Efficiency} = \frac{\text{Useful Energy Output}}{\text{Total Energy Input}} \times 100\%

💡Examples

Problem 1:

If a country has an estimated reserve of 80,000,00080,000,000 tonnes of coal and consumes 34,567,89234,567,892 tonnes in a decade, how much coal is left? Show the calculation.

Solution:

80000000−3456789245432108\begin{array}{r} 80000000 \\ -34567892 \\ \hline 45432108 \end{array}

Explanation:

To find the remaining coal, we subtract the consumed amount from the total reserves. The remaining coal is 45,432,10845,432,108 tonnes.

Problem 2:

Identify the primary chemical element found in coal and write its symbol using LaTeXLaTeX.

Solution:

The primary element is Carbon, and its symbol is CC.

Explanation:

Coal is formed through the process of carbonization of plant matter, resulting in a substance that is predominantly Carbon (CC).

Problem 3:

Why is CNGCNG preferred over Petrol in public transport?

Solution:

CNGCNG (Compressed Natural Gas) is a cleaner fuel because it produces less CO2CO_{2} and harmful pollutants compared to Petrol.

Explanation:

Natural gas burns more completely than liquid petroleum products, making it more environmentally friendly for city transport.