What amount of energy is released when 1 kg of coal is burned?

The correct answer is 1) 3 × 10⁷ J.

Key Points

• Burning 1 kg of coal releases approximately 3 × 10⁷ joules of energy.
• This amount of energy is equivalent to 30 megajoules.
• Coal is a fossil fuel that contains a significant amount of carbon, which when burned, releases energy.
• The energy content of coal can vary depending on the type and quality of the coal.
• Coal is widely used in power generation due to its high energy content and availability.

Additional Information

• Types of Coal:
  • Anthracite: The highest grade of coal, containing the highest carbon content and energy.
  • Bituminous: A commonly used type of coal with high heating value.
  • Sub-bituminous: Has lower heating value and carbon content compared to bituminous coal.
  • Lignite: Also known as brown coal, has the lowest carbon content and energy.
• Combustion Process:
  • During combustion, coal reacts with oxygen to produce carbon dioxide, water, and energy.
  • Complete combustion requires an adequate supply of oxygen to ensure maximum energy release.
• Environmental Impact:
  • Burning coal releases carbon dioxide (CO₂), a greenhouse gas contributing to global warming.
  • It also releases pollutants like sulfur dioxide (SO₂) and nitrogen oxides (NOₓ), which can cause acid rain and respiratory issues.
• Alternative Energy Sources:
  • Renewable energy sources like solar, wind, hydroelectric, and geothermal are being promoted to reduce dependence on fossil fuels.
  • These sources are more sustainable and have a lower environmental impact compared to coal.