What are carbon compounds?
Carbon compounds are chemical compounds that contain the element carbon. Most are made by, or come from, living things, which is why the study of them is often called organic chemistry. Sugar in your teh tarik, the ethanol in hand sanitiser and the fibres in a cotton shirt are all carbon compounds. A few carbon substances such as carbon dioxide, carbonates and diamond are usually treated as inorganic.
Why carbon forms so many compounds
A carbon atom has four valence electrons, so it forms four covalent bonds. This lets carbon atoms join to one another in long chains, branched chains and rings, a special ability called catenation. Because of catenation, carbon can build millions of different molecules with hydrogen, oxygen and nitrogen.
The bonds carbon forms are strong covalent bonds, which is why many carbon compounds are stable and do not conduct electricity. Carbon can also bond to itself with single, double or even triple bonds, giving families such as the alkanes, alkenes and alcohols. This variety is the reason carbon lies at the heart of all living tissue and of most modern materials, from petrol and plastics to medicines and food.
Key idea
One carbon atom shares its 4 outer electrons to make 4 covalent bonds. Long carbon chains plus other atoms (H, O, N) give a huge variety of compounds.
Sources of carbon compounds
- Living organisms – plants and animals make carbohydrates, proteins and fats.
- Fossil fuels – petroleum and natural gas are mixtures of carbon compounds formed from ancient organisms.
- Laboratory synthesis – plastics, medicines and dyes are made industrially.
Example
Petroleum pumped from beneath the Malaysian seabed is separated at a refinery into petrol, diesel and cooking-gas, all of which are carbon compounds used every day.
Remember
Not every substance with carbon is 'organic': carbon dioxide, carbon monoxide and metal carbonates are counted as inorganic compounds.