Beginner Topic 400 of 1102 Thermodynamics & Energetics
Fossil Fuels
Coal, oil and natural gas formed from ancient organisms, burned for energy and releasing CO2.
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In-depth explanation of Fossil Fuels
Fossil fuels, including coal, petroleum and natural gas, formed over millions of years from the remains of ancient plants and marine organisms buried and transformed under heat and pressure. They are concentrated chemical energy stores that supply most of the world's primary energy and feed electricity generation, transport and industry. Combustion of fossil fuels releases the energy stored in their hydrocarbons while producing carbon dioxide, which accumulates in the atmosphere and contributes to climate change. Their energy content and reliability make them economically dominant, but their emissions drive interest in alternatives. Understanding their combustion enthalpies is central to assessing their environmental impact.
Going deeper: Fossil Fuels
Key ideas: Typical combustion produces CO2 and H2O, with sulfur and nitrogen oxides as byproducts. The CO2 per unit energy decreases from coal to oil to natural gas because of the rising ratio of hydrogen to carbon. Reserves are finite on human time scales.
Common mistakes and connections: Do not regard them as pure hydrocarbons, since coal contains sulfur and mineral matter. Another misconception is that carbon dioxide is just a pollutant, when it is a necessary product of complete combustion, which is why capture and storage are needed. The topic connects to climate chemistry and to enthalpy of combustion.
Visualization of Fossil Fuels
Fossil fuels supply roughly four fifths of world primary energy, split among oil, coal and natural gas; the remainder is nuclear, hydro and renewables. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Burning 1 kg of pure carbon releases about 3.7 kg of carbon dioxide, since each carbon atom gains two oxygen atoms.
Frequently asked questions about Fossil Fuels
What is Fossil Fuels?
Coal, oil and natural gas formed from ancient organisms, burned for energy and releasing CO2.
Is Fossil Fuels a beginner, intermediate or advanced topic?
Fossil Fuels is a beginner topic in Thermodynamics & Energetics. It needs no earlier chemistry lessons and is a good starting point.
What should I learn before Fossil Fuels?
Study these earlier topics in Thermodynamics & Energetics first: Thermodynamic vs Kinetic Control, Fuel Calorific Value, Energy Density.
What comes after Fossil Fuels?
The next topics in Thermodynamics & Energetics are Hydrogen as Fuel and Biofuels.
Can I practise Fossil Fuels with quizzes?
Yes. The interactive lesson includes a self-check question on Fossil Fuels, and the Thermodynamics & Energetics quiz draws on every topic in this area.
Where Fossil Fuels fits in Thermodynamics & Energetics
Fossil Fuels is topic 72 of 91 in Thermodynamics & Energetics.