Alkanes Alkanes are hydrocarbons in which the carbon atoms are held together by single bonds. Alkanes also called parafins. Their general formula is C n H 2n+2 for molecules which do not contain ring structures.Alkanes are also called saturates or saturated hydrocarbons. The carbon atoms that make up the carbon backbone are linked together to form a chain (linear or branched alkanes), a circle (cyclic alkenes), or a mixture of both. The alkanes are distinguished from the other hydrocarbons by the fact that they are completely saturated with hydrogen. This means that no additional hydrogen atoms can be added to these hydrocarbons without destroying the carbon backbone. Alkanes are in some respect the most boring of the organic compounds, since they are unreactive (mostly) towards acids, bases, oxidizing agents, reducing agents, and most of the other reagents that organic chemistry have in their arsenals. On the other hand, alkanes are important for their ability
Valence Bond Theory Valence bond theory was proposed by Heitler and London in 1927 based on atomic orbitals and their configuration. According to valence bond theory: A covalent bond is formed when pure, valence atomic orbital of one atom overlaps with another pure, valence atomic orbital of another atom. During covalent bond formation energy releases that means stability increases. each of the overlapping orbitals contains the unpaired electron of opposite spin.The electron pair is shared by both the atoms. The strongest bond is formed when the orbitals of the two atoms overlap to the maximum extent. based on the overlapping of orbitals, two types of covalent bonds are formed. These are known as sigma and pi bonds. Sigma bonds are formed by the end-to-end overlap of atomic orbitals along the inter-nuclear axis known as a head-on or axial overlap. Types of orbital overlap :- Depending upon the type of overlapping, the covalent bonds are of two types, known as sigma (σ ) and pi (π) bond