A general definition states that the Kekule structure is a Lewis structure in which the lines are used to represent the bonded electron pairs from the covalent bonds. From the organic chemistry perspective, the structural formula of benzene represented as a hexagonal ring with alternate single and double bonds between the carbon atoms, every carbon atom being tetravalent and incident with exactly one double bond is also referred as a Kekule structure. The Kekule structure concept was first stated by August Kekule in 1865, when he proposed the structural formula of benzene as a cyclic molecule with the form of a regular hexagon. After years of studies, scientists determine that there are a series of problems which arise in the Kekule theory for benzene. First is represented by the low reactivity of benzene, meaning that benzene does not react with alkenes and bromine water, as it should.