write down the nomenclature and classification of alkanes and cycloalkanes with examples and draw the branched and unbranched alkanes.
Answers
Most reactions of organic compounds take place at or adjacent to a functional group. In order to establish a baseline of behavior against which these reactions may be ranked, we need to investigate the reactivity of compounds lacking any functional groups. Such compounds are necessarily hydrocarbons, made up of chains and rings of carbon atoms bonded to a full complement of hydrogen atoms (all carbons are sp3 hybridized). From the previous discussion of formula analysis, the formulas for such hydrocarbons will be CnH(2n+2–2r) , where n is the number of carbon atoms and r is the number of rings. Hydrocarbons of this kind are classified as alkanes or cycloalkanes, depending on whether the carbon atoms of the molecule are arranged only in chains or also in rings. Although these hydrocarbons have no functional groups, they constitute the framework on which functional groups are located in other classes of compounds, and provide an ideal starting point for studying and naming organic compounds. Alkanes and cycloalkanes are termed saturated, because they incorporate the maximum number of hydrogens possible without breaking any carbon-carbon bonds. They are also members of a larger class of compounds referred to as aliphatic. Simply put, aliphatic compounds are compounds that do not incorporate any unsaturated aromatic rings in their molecular structure.