Chlorobenzene is extremely less reactive towards a nucleophilic substitution reaction. Give two reasons for the same?
1) Resonance effect: The electron pair on chlorine atom is in conjugation with the electrons of the benzene ring which results in the following resonance structures:
This results in delocalization of the electrons of C- Cl bond and a partial double bond character develop in the bond, which makes it difficult for the nucleophile to cleave the C- Cl bond.
2) The nucleophile suffers repulsion from the increased electron density on the benzene ring, as a result, the nucleophile is unable to make a close approach for the attack on the molecule.
After watching a programme on TV about the adverse effects of junk food and soft drinks on the health of school children, Sonali, a student of Class XII, discussed the issue with the school principal. Principal immediately instructed the canteen contractor to replace the fast food with the fibre and vitamins rich food like sprouts, salad, fruits etc. This decision was welcomed by the parents and the students.
After reading the above passage, answer the following questions:
(a) What value are expressed by Sonali and the Principal of the school?
(b) Give two examples of water-soluble vitamins.
Write the names and structure of the monomers of the following polymers:
(i) Buna- S
(ii) Neoprene
(iii) Nylon-6, 6
