2nd Year Chemistry Chapter 9 Notes

• Important 2nd year chemistry chapter 9 mcqs for Intermediate part-II students.
• What are aromatic hydrocarbons? Give two examples.
• How are the aromatic hydrocarbons classified?
• What are Monocyclic Aromatic Hydrocarbons? Give examples.
• Important 2nd year chemistry chapter 9 short questions for Intermediate part-II students.
• What are Polycyclic Aromatic Hydrocarbons? Give examples.
• What are fused ring aromatic compounds? Give examples. 
• What are polycyclic aromatic hydrocarbons? Give examples. 
• Important 2nd year chemistry chapter 9 exercise for Intermediate part-II students.
• Give X-ray studies of benzene.
• Compare reactivity of alkanes, alkenes and benzene.
• Write general mechanism of electrophilic substitution reactions in benzene OR Give general pattern of reactivity of benzene towards electrophiles.
• Important 2nd year chemistry chapter 9 solved exercise for Intermediate part-II students.
• Benzene has three pi bonds. Prove it by two points.
• Predict major product of the bromination of benzene. Also give equation.
• Benzene can be prepared commercially from acetylene. Give reaction with conditions.
• How Hexane and Heptane can give Benzene and Toluene respectively?
• Important 2nd year chemistry chapter 9 solved exercise pdf for Intermediate part-II students.
• How Benzene can be converted to Acetophenone? Give mechanism.
• Give two reasons that rule out straight chain structures of benzene. 
• Define Resonance and write down resonance structures of benzene. 
• Important 2nd year chemistry chapter 9 important short questions for Intermediate part-II students.
• Prove that Benzene has cyclic structure. 
• What is Wurtz-Fittig reaction? Give an example. 
• Define resonance energy. Give resonance energy of benzene. 
• What is aromatization?
• Important 2nd year chemistry chapter 9 important long questions for Intermediate part-II students.
• How will you synthesize benzene from Ethyne?
• Give mechanism for nitration of benzene. OR What is meant by nitration of benzene?
• How benzene is converted into Maleic acid by catalytic oxidation?
• What happens when benzene is burnt in free supply air? Give equation.
• Important 2nd year chemistry chapter 9 Important Questions for Intermediate part-II students.
• Give names and possible isomeric structures of the following: (i) Xylenes (ii) Trimethylbenzene (iii) Bromonitrotoluene
• What happens when benzene is heated with conc. H2SO4 at 250 ⁰C?
• What happens when chlorine is passed through benzene in sunlight?
• What happens when a mixture of benzene vapours and air are passed over heated vanadium pentaoxide?
• Important 2nd year chemistry chapter 9 solved exercise short questions for Intermediate part-II students.
• How will you prepare p-chloronitrobenzene from benzene in two steps?
• Predict the major products of bromination of benzaldehyde
• Predict the major products of bromination of phenol.
• Important 2nd year chemistry chapter 9 long questions for Intermediate part-II students.
• INTRODUCTION: The term aromatic was derived from the Greek word ‘aroma’ meaning “fragrant” and was used in Organic Chemistry for a special class of compounds. These compounds have a low hydrogen to carbon ratio in their molecular formula and have a characteristic odour. However, it was soon realized that many aromatic compounds are odourless whereas many others are fragrant though they are not aromatic.
• Important 2nd year chemistry chapter 9 long questions for Intermediate part-II students.
• Further, when aromatic compounds of higher molecular mass were subjected to various methods of degradation, they often produced benzene or derivatives of benzene. It was observed that almost all the aromatic compounds have a six carbon unit in their molecules like benzene. Hence, benzene was recognized as the simplest and the parent member of this class of compounds. So aromatic hydrocarbons include benzene and all those compounds that are structurally related to benzene.
• Important 2nd year chemistry chapter 9 exercise short questions for Intermediate part-II students.
• It appears from the definition of aromatic hydrocarbons that any study of this class of compounds must begin with the study of benzene. Benzene has characteristic structural features. It has a regular planar hexagonal structure. On the basis of the number of benzene rings aromatic hydrocarbons can be categorized into following classes.
• NOMENCLATURE: (Monocyclic Aromatic Hydrocarbons and their Derivatives): The nomenclature of the aromatic hydrocarbons is much more complex than that of aliphatic hydrocarbons. The system used for naming benzene and its derivatives generally depends on the number of substituents on the benzene ring. 
• Some important rules of naming are given below:
• 1. Mono-substituted benzene derivatives are named by prefixing benzene with the name of the substituent. The whole name is written as one word, e.g.
• 2. There are certain monosubstituted benzene derivatives which are given the special names, like methylbenzene as toluene, hydroxybenzene as phenol etc.
• All the six positions in benzene are exactly equivalent so there is only one monosubsituted benzene. When a hydrogen atom is removed from benzene, we get a phenyl group symbolized by C6H5- or Ph-. Substituted phenyl groups are called aryl groups.