Q21 of 26 Page 1

(a) Identify the monomer in the following polymeric structure:


(b) Which one of the following is an Elastomer?


(c) On the basis of forces between their molecules in a polymer, to which class does polyester belong?


(a) Caprolactum monomer of nylon-6


Urea-formaldehyde, resin, Buna-S, PVC


(b) Buna-S


Elastomers are polymers which stretch on applying pressure and return to their original form on removal of pressure.


(c) Polyesters belong to the class of fibres based on forces between their molecules. Fibres are polymers which possess high tensile strength due to strong intermolecular bonding(like hydrogen bonding).


More from this chapter

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19

Give reasons for the following:

(a) Aldehydes and ketones have lower boiling points than corresponding alcohols.


(b) Chloroacetic acid is stronger than acetic acid.


(c) Formaldehyde does not take part in aldol condensation.


 20

An aromatic compound A on treatment with ammonia followed by heating forms compound B which on heating with Br2 and KOH forms compound C having molecular formula C6H7N. Give the structures of A,B and C.

 22

Give one example for each of the following:

(a) An artificial sweetener whose use is limited to cold drinks.


(b) A non-ionic detergent.


(c) A pain reliever used for relief from severe pain like post-operative pain.


 23

Aadik Behl was playing in the park with his friends. While running to catch a ball, one of his friends, Saurish fell down and he had a cut on his hand due to which lot of blood was coming out. Aadik took him to his house and applied alum on the cut due to which the blood stopped.

Answer the following questions:


(a) Why did the blood stop after applying alum on the cut?


(b) Alum is used for purification of water. Why?


(c) Artificial rain is caused by spraying silver iodide on clouds. Give reason.


(d) What are the values (any two) displayed by Aadik?