Class 12th

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.

This is a multiple choice answer as classified in NCERT Exemplar

Option (D)

Explanation: Glycogen is a branched polymer of glucose found in the liver, muscles, and brain of animals.

Yes, MAAC, South Extension accept Class 12th marks for admission. The basic eligibility for course admission is to pass Class 12. MAAC, South Extension offers over 12 certificate courses under multiple streams, such as VFX, Web & Graphic Design, Animation, etc. Apart from the certificate courses, the institute also offers short-term courses, and their duration is less than 12 months. 

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans: While manufacturing tyre rubber, 5 % sulfur is used as a crosslinking agent. A natural linear polymer of 2-methyl-1, 3-butadiene becomes hard on treatment with sulfur and forms vulcanised rubber. The structure of the product formed is,

This is a Long Answer Type Questions as classified in NCERT Exemplar

Thermoplastic polymer

Thermoplastic polymers are linear or slight branched-chain polymers. In this type of polymer, the strong intermolecular force of attraction is present between elastomers and fibers. This type of polymer softens on heating and hardens on cooling. For example, polythene, polystyrene and polyvinyl.

Thermosetting polymer

Thermosetting polymers are cross-linked polymers. These polymers on heating undergo cross-linking in molds. They become infusible on heating so, cannot be reused again. For example, Bakelite and urea-formaldehyde resins.

This is a Long Answer Type Questions as classified in NCERT Exemplar

Ans:

This is a Long Answer Type Questions as classified in NCERT Exemplar

In rubber, the polymer chain are held together by the weakest force of attraction. While, in plastic, the strong intermolecular force of attraction is present between elastomers and fibres.

In rubber, a few crosslinks are introduced between the chain, while plastics are linear or slightly branched molecules which gets soft on heating and hard on cooling.