Benzene, a six-carbon ring with alternating double bonds, exhibits unique chemical stability compared to aliphatic compounds. Its reactions often involve substitution rather than addition reactions. Here are some fundamental chemical reactions of benzene: 1. Substitution Reactions: (a) Halogenation: Benzene can undergo halogenation in the presence of a halogen (e.g., chlorine or bromine) and a catalyst. … Read more
Benzene’s special stability is due to the delocalized π molecular orbital formation. The magnitude of this extra stability can be estimated by measuring the changes in the heat of hydrogenations associated with reactions. Hydrogenation of cyclohexane evolves 28.6 kcal/mol, a value typical for hydrogenation of alkenes. Fig makes these energy relationships more evident. The 36kcal … Read more
Introduction The structure of benzene is best described in the modern molecular orbital theory. All six carbon atoms in benzene are sp2 hybridized. The sp2 hybrid orbitals overlap with each other and with the s orbitals of the six hydrogen atoms forming C-C and C-H σ bonds. Formation of σ- bonds in benzene Since the … Read more
In the case of benzene, Kekule’s structures (1) and (2) represent the resonance structures. The actual structure of the molecule may be represented as a hybrid of these two resonance structures or by the single structural formula (3). It should be clearly understood that the resonance structures (1) and (2) are not the actual structures … Read more
Introduction: In 1865, Kekule suggested benzene consisted of a cyclic planar structure of six carbons with alternate double and single bonds. To each carbon was attached one hydrogen. Benzene, according to this proposal, was simple 1,3,5-cyclohexatriene. Kekule’s structure of benzene explained satisfactorily the following points. 1. That benzene contains three double bonds. 2. All six … Read more
Introduction: The cyclic structure of benzene, with alternating single and double bonds, has been a subject of considerable scientific interest. Several lines of evidence support the cyclic, rather than the classical Kekulé structures with fixed single and double bonds, for the benzene molecule. Here are some key pieces of evidence: (1) Substitution of Benzene: Benzene … Read more
📚 Welcome to pharmacareerinsider.com – Your Gateway to Academic Excellence! 🌐 Unlock the secrets to success with our extensive collection of previous year’s question papers, meticulously curated to elevate your learning experience. 🚀 Embark on a journey of preparation and mastery as you download these valuable resources tailored to help you navigate the challenges of … Read more
📚 Welcome to pharmacareerinsider.com – Your Gateway to Academic Excellence! 🌐 Unlock the secrets to success with our extensive collection of previous year’s question papers, meticulously curated to elevate your learning experience. 🚀 Embark on a journey of preparation and mastery as you download these valuable resources tailored to help you navigate the challenges of … Read more
📚 Welcome to pharmacareerinsider.com – Your Gateway to Academic Excellence! 🌐 Unlock the secrets to success with our extensive collection of previous year’s question papers, meticulously curated to elevate your learning experience. 🚀 Embark on a journey of preparation and mastery as you download these valuable resources tailored to help you navigate the challenges of … Read more
📚 Welcome to pharmacareerinsider.com – Your Gateway to Academic Excellence! 🌐 Unlock the secrets to success with our extensive collection of previous year’s question papers, meticulously curated to elevate your learning experience. 🚀 Embark on a journey of preparation and mastery as you download these valuable resources tailored to help you navigate the challenges of … Read more
