Chemistry

This is a multiple choice answer as classified in NCERT Exemplar

Option (C) and (D)

Explanation: Fibers are thread-forming solids. They possess high tensile strength and high modulus. They have strong intermolecular forces of attraction like hydrogen bonding. Nylon and Terylene are used as fibers.

This is a multiple choice answer as classified in NCERT Exemplar

Option (A) and (D)

Explanation: Thermoplastic polymers are linear or slight branched-chain polymers. This type of polymer softens on heating and hardens on cooling. For example, Teflon and polystyrene are thermoplastic polymers.

So, options (A) and (D) are correct.

This is a multiple choice answer as classified in NCERT Exemplar

Option (A) and (C)

Explanation: Thermosetting polymers are cross linked polymers. These polymers on heating undergo cross linking in moulds. They become infusible on heating so cannot be reused again.

This is a multiple choice answer as classified in NCERT Exemplar

Option (B) and (C)

Explanation: Buna-S and neoprene are the polymers that needs at least one diene monomeric unit. Buna- S is a polymer formed from the polymerization of 1,3-butadiene and styrene. While, Neoprene is formed by the polymerisation of chloroprene.

This is a multiple choice answer as classified in NCERT Exemplar

Option (D)

Explanation: The given structure is caprolactam. Nylon-6 is prepared from the monomer caprolactam. It is obtained by heating caprolactam with water at a high temperature.

This is a multiple choice answer as classified in NCERT Exemplar

Option (B)

Explanation: Low-density polythene is obtained from the polymerization of ethane under high pressure and temperature. Low-density polyethylene is tough, a poor conductor of electricity and has a highly branched structure.

Low-density polythene is not hard because branched structure prevents stacking and thus, reduces the intermolecular force of attraction.

So, option (B) is correct.

This is a multiple choice answer as classified in NCERT Exemplar

Option (A)

Explanation: Dacron or Terylene is formed by the condensation polymerization of ethylene glycol and phthalic acid with the elimination of water molecules. The structure of Terylene is,

This is a multiple choice answer as classified in NCERT Exemplar

Option (C)

Explanation: PHBV (Poly beta-hydroxybutyrate co-beta-hydroxy valerate) is a biodegradable polymer. It undergoes bacterial degradation in the environment. The structure is shown as,

This is a multiple choice answer as classified in NCERT Exemplar

Option (B)

Explanation: Polyacrylonitrile is used as a wool substitute in the manufacture of commercial fibers such as orlon or acrilan.

This is a multiple choice answer as classified in NCERT Exemplar

Option (A)

Explanation: Semi-synthetic polymers are obtained from natural polymers. Cellulose derivatives like cellulose nitrate, cellulose acetate rubber are examples of semi-synthetic polymers.

Cis-polyisoprene is not a semi-synthetic polymer while other examples are semi-synthetic polymer.