Question

Consider the following statements,
I. Weakest intermolecular forces are present in elastomers.
II. Fibers possess crystalline nature.
III. Ionic bonds are present in thermoplastic polymers.
Select the correct option:
A. I and II
B. II and III
C. I and III
D. I, II and III

Answer 1

Hint – In order to solve this problem one needs to know that the structures of polymers / elastomers are such that they can stretch easily and its bond is very weak. Fibers have strong intermolecular forces of attraction and no ionic bonds are present in thermoplastic polymers.

Complete step-by-step answer:
(I) In elastomers the chains which are polymeric are held by weak intermolecular forces of attraction and because of those forces polymers are able to stretch itself.
(II) Fibres have intermolecular hydrogen bonding which are generally strong in nature. They are thread forming solids, they have high tensile strength and high modules and because of this only we can say there is intermolecular hydrogen bonding. Because of such strong forces fibres are crystalline in nature.
(III) No, ionic bonds are present in thermoplastics. Ionic bonds to be present there must be ions which thermoplastics do not have.
Hence, the statements are (I) and (II).
So, the correct option is A.

Note – In such problems of chemistry you must have to read the concepts and grab it since in chemistry there are no more logical ways to remember the concepts you just have to learn it. Since, there are more exceptions so we cannot say all the time logic works in this subject. Students can imagine and read the books to remember these concepts that which molecule will be having which bond one can also determine it by looking out the elements but there is one thing in this particular subject and that is exceptions so we have to read it at-least once such that we could remember it.