Question on Aromatic Substitution
In the following reaction, which of the two products will be the major product? Why?
Question on Isomerism
Two isomeric compounds (A) and (B), C10H12O don’t have –OH group and discharge colour of bromine water. Each is vigorously oxidised to 4-methoxy benzoic acid. Ozonolysis of (A) and (B) give the same product. Which type of isomerism is present in (A) and (B)?
Question on Electrophilic Aromatic Substitution
Which among (a) Nitrobenzene and (b) benzene, is a suitable solvent for the Friedel - Craft alkylation of para - bromo benzene?
Answer:
Among the three aromatic compounds mentioned in the question, benzene is the most reactive towards an electrophile followed by bromo benzene and then by nitro benzene. If we want the electrophile to substitute on bromo benzene then a solvent which is less reactive than itself towards the reagent should be used. So, nitrobenzene is a suitable solvent in this case.
Question on Nitration
Nitrobenzone can be prepared from benzene by using a mixture of conc. HNO3 and conc. H2SO4. In the nitrating mixture, what is the role of H2SO4?
Answer:
H2SO4 makes HNO3 act as a base and produce nitronium ion (NO2+).
Snake and Structure o Benzene
Benzene is one of the very important compounds of Chemistry. It is the starting material for lots of commercially important compounds.
Micheal Faraday, first reported the discovery of Benzene and called it bicarburet of hydrogen. Many scientists later worked on Benzene and started reporting easier methods for its extraction and multiple uses.
The molecular formula of Benzene was confirmed to have six carbons and six hydrogens. As a carbon atom is capable of forming four bonds the molecular formula of benzene showed that the molecule was highly unsaturated.
Some Proposed Structures of Benzene
Among the lot of scientists who were making attempts to arrive at a structure of benzene, was Kekulé. Kekulé had already spent many years attempting to arrive at a logical structure for benzene. One day while working on the same he fell asleep and had a dream in which he saw a snake moving and grab its own tail forming a cycle. Kekulé immediately realized that the structure of benzene should be a ring.
Resonance Stabilized Structure of Benzene
He then published the structure of benzene as one having a six membered ring of carbon atoms with alternate single and double bonds and also a hydrogen attached to every carbon atom. This he did around 40 years after benzene was discovered.
That is how a snake is related to the structure of Benzene.
:)
Question on Aromatic Compounds
Which one of the following compounds does not show aromaticity?
Answer:
compound (d) does not show aromaticity as there is a break in conjugation of the pi-electrons present in it.
