Chemistry is in the air we breathe, the food we eat and everything we use. Among all chemical compounds, hydrocarbons are the most important: the whole civilisation is driven by them because they make up the fossil fuels – petroleum, coal and natural gas.
1. Hydrocarbons
Hydrocarbons are organic compounds consisting of carbon and hydrogen atoms. They are combustible and on burning produce a large amount of heat energy along with carbon dioxide and water vapour. Hence many hydrocarbons are used as fuels.
Sources
- Hydrocarbons occur naturally in fossil fuels like crude oil, natural gas and coal. They are also present in different trees and plants.
- About 300 million years ago buried plants and animals were compressed by temperature and pressure into oil and natural gas, found in porous rocks below oceans and extracted by drilling.
Properties
- Most hydrocarbons are insoluble in water.
- They are less dense than water, so they float on top of water.
- They can be gases (methane, propane), liquids (hexane, benzene) or waxes (paraffin).
- They can make bonds with one another – this property is called catenation (chain formation), due to which they form more complex molecules.