Why are carbon and its compounds used as fuels for most applications?
Carbon and its compounds are used as fuels for most applications because they are major sources of fuels. These compounds are readily available and widely used, as seen with methane, which is a major component of bio-gas and Compressed Natural Gas (CNG).
Carbon is a versatile element that forms a large variety of compounds due to its tetravalency and the property of catenation. This versatility allows carbon to form numerous compounds through covalent bonds with elements like hydrogen, oxygen, and others, making them suitable for use as fuels in various applications.
Explanation
The textbook context directly states that 'Carbon and its compounds are some of our major sources of fuels.' It also provides the example of methane being widely used as a fuel and being a major component of bio-gas and CNG. The versatility of carbon due to tetravalency and catenation enables the formation of numerous compounds that serve as fuel sources. The answer stays strictly within the provided context without adding external knowledge about combustion properties or calorific values.