Oil, in a general sense, is a chemical compound that is not miscible with water, and is in a liquid state at ambient temperatures. Such substances are sometimes described as hydrophobic (meaning water hating) or lipophilic (meaning fat loving). The following is brief list of uses for oil:
- Cooking oil - Edible vegetable and animal oils are frequently used in cooking, due to their ability to reach higher temperatures than water. They also serve as a flavour enhancer and as a supporting medium for vitamins and aromas.
- Fuel oil -Oils contain a high amount of stored energy, which can be used for heating and powering combustion engines. Oils used for this purpose are usually derived from petroleum, but biological sources of energy are being evaluated as an alternative to the increasingly expensive crude oil.
- Lubrication - Due to their non-polarity, oils do not easily adhere to other substances. This makes them useful as lubricants for various engineering purposes. Suitable oils are often found in the mineral spectrum, as biological oils degrade quickly in most environmental conditions.
- Petrochemistry - Petrochemistry is the process of refining crude oil into useful raw materials, plastics, and other oils.
- Heat transport - Many oils have higher boiling points than water and lower electrical conductivity, allowing them to be used for liquid cooling systems, especially where electricity is used.
- Painting - Color pigments can be easily dissolved in oil, making oil suitable as supporting medium for paints. The slow drying process and miscibility of oil facilitates a realistic style. This method has been used since the 15th century.