Industrial Chemistry and Water Treatment

Alkenes, Alkynes and Aromatic Compounds

Alkenes contain at least one double bond. Alkynes contain at least one triple bond. Most of these types of hydrocarbons can exist with the same chemical formula in different form or chemical structure. When a compound has the same chemical formula but two possible structures, these two structures are called isomers. Alkenes are unsaturated since they have a double covalent carbon bond. Alkenes have the general formula C_nH_2n. Alkynes (acetylenes) are unsaturated encyclical hydrocarbons which contain one or more triple bonds between atoms of carbon. The general formula for alkynes is C_nH_2n-2 
Aromatic hydrocarbons contain the 6-membered benzene ring structure that is characterized by alternating double bonds. Thus, they have formulas that can be drawn as cyclic alkenes, making them unsaturated. Benzene, C₆H₆, is the simplest member of a large family of hydrocarbons, called aromatic hydrocarbons.  Aromatic compounds more readily undergo substitution reactions than addition reactions; replacement of one of the hydrogen atoms with another substituent will leave the delocalized double bonds intact.