Question 1

Which of the following is a cross-linked, thermosetting polymer?

Accepted Answer

Bakelite is formed by the condensation reaction of phenol with formaldehyde. It is a highly cross-linked, thermosetting polymer which, once molded, cannot be remolded or reshaped by heating. PVC, Polystyrene, and PTFE (Teflon) are examples of thermoplastic polymers, which can be repeatedly softened by heating and hardened by cooling. Answer: Bakelite

Question 2

Which of the following is fully Fluorinated polymer?

Accepted Answer

Teflon is the commercial name for polytetrafluoroethylene (PTFE). The monomer of Teflon is tetrafluoroethylene, which has the chemical formula CF_2=CF_2. Since all the hydrogen atoms in the ethylene monomer are replaced by fluorine atoms, Teflon is a fully fluorinated polymer. PVC (polyvinyl chloride) contains chlorine and hydrogen, neoprene contains chlorine and hydrogen, and Buna-S is a hydrocarbon polymer containing only carbon and hydrogen. Answer: Teflon

Question 3

Identify the monomers used for preparation of glyptal?

Accepted Answer

Glyptal is a condensation polymer belonging to the class of polyesters. It is synthesized by the condensation polymerization of ethylene glycol (ethane-1,2-diol) and phthalic acid (benzene-1,2-dicarboxylic acid). The polymerization reaction involves the elimination of water molecules to form ester linkages between the monomers. Answer: Ethylene glycol and phthalic acid

Question 4

Which from following polymers is used to obtain shampoo bottles?

Accepted Answer

High-density polyethylene (HDPE) is a tough, hard, and rigid polymer with high tensile strength and excellent chemical resistance. Due to these properties, it is widely used in the manufacture of household articles like buckets, dustbins, pipes, and various types of bottles, including shampoo bottles and milk jugs. Low-density polyethylene (LDPE) is typically used for flexible items like squeeze bottles and packaging films, while Polypropylene (PP) is used for ropes and toys, and Polystyrene (PS

Question 5

Which from following polymers is obtained by condensation polymerization method?

Accepted Answer

Polythene is an addition polymer formed by the repeated addition of ethene monomers. Polyacrylonitrile is an addition polymer formed by the addition polymerization of acrylonitrile. Teflon is an addition polymer formed by the addition polymerization of tetrafluoroethene. Dacron (also known as terylene) is a condensation polymer formed by the condensation polymerization of ethylene glycol and terephthalic acid with the elimination of water molecules. Answer: Dacron

Question 6

Which from following polymers is obtained by condensation polymerisation method ?

Accepted Answer

To determine which polymer is obtained by condensation polymerisation, let us analyze each option: 1. [\, CF _2 - CF _2\,]_n is Teflon (Polytetrafluoroethylene). It is formed by the addition polymerisation of tetrafluoroethene. 2. [\, CH _2 - CH _2\,]_n is Polythene. It is formed by the addition polymerisation of ethene. 3. [\, NH - ( CH _2)_5 - CO \,]_n is Nylon 6. It is synthesized by the ring-opening polymerisation of caprolactam. Since no small molecule is eliminated during the process, it i

Question 7

Which from following polymers is classified as branched chain polymer?

Accepted Answer

Low density polythene (LDPE) is synthesized by free radical polymerization, which involves chain transfer reactions that lead to a highly branched structure. High density polythene (HDPE) and polyvinyl chloride (PVC) are linear polymers. Melamine-formaldehyde resin is a cross-linked or network polymer. Answer: Low density polythene

Question 8

Identify thermosetting polymer from following.

Accepted Answer

Thermosetting polymers are cross-linked or heavily branched molecules, which on heating undergo extensive cross-linking in moulds and become infusible. These cannot be reused. Examples of thermosetting polymers include Bakelite, urea-formaldehyde resins, and melamine-formaldehyde resins. Polystyrene is a thermoplastic polymer. Buna-S is an elastomer. Terylene is a fibre. Answer: Ureaformaldehyde resin

Question 9

Identify ureaformaldehyde resin from following polymers?

Accepted Answer

Urea-formaldehyde resin is a condensation polymer formed by the reaction between urea (NH_2-CO-NH_2) and formaldehyde (HCHO). The initial reaction involves the formation of methylol urea derivatives, which then undergo condensation with the elimination of water molecules to form a cross-linked polymer network. The repeating unit of the urea-formaldehyde polymer chain is derived from linking the nitrogen atoms of urea with the methylene (-CH_2-) group from formaldehyde. The repeating unit is [-NH

Question 10

Which of the following is the use of HDPE ?

Accepted Answer

High-density polyethylene (HDPE) is a tough, hard, and rigid polymer. It is widely used in the manufacture of buckets, dustbins, bottles (such as shampoo bottles), and pipes. Low-density polyethylene (LDPE) is highly branched and flexible, making it suitable for shopping bags, squeeze bottles, toys, and flexible pipes. Therefore, HDPE is used to prepare shampoo bottles. Answer: To prepare shampoo bottles

Question 11

What is a starting material used to obtain viscose rayon ?

Accepted Answer

Viscose rayon is a semi-synthetic polymer. It is obtained by the chemical treatment of natural cellulose, which is typically sourced from wood pulp. The cellulose is first dissolved in an alkaline solution of sodium hydroxide and then treated with carbon disulfide to form cellulose xanthate. This is further dissolved in dilute sodium hydroxide to form a viscous solution called viscose, which is then extruded into an acid bath to regenerate cellulose in the form of fine filaments known as viscose

Question 12

Identify the use of LDP from following.

Accepted Answer

Low Density Polyethylene (LDP) is widely used for the preparation of flexible pipes for agriculture, irrigation, domestic water line connections, and as insulation for electric cables. High Density Polyethylene (HDP) is used for the manufacture of buckets, dustbins, and rigid pipes. Teflon (Polytetrafluoroethylene) is used for making non-stick cookware. Nylon 6 is used for making tyre cords, fabrics, and ropes. Answer: Preparation of pipes for irrigation

Question 13

Which from following polymers is NOT obtained by addition polymerisation method?

Accepted Answer

Teflon is an addition polymer of tetrafluoroethene. Polyacrylonitrile is an addition polymer of acrylonitrile. LDP (Low-density polyethylene) is an addition polymer of ethene. PHBV (Poly -hydroxybutyrate-co- -hydroxyvalerate) is a condensation polymer of 3-hydroxybutanoic acid and 3-hydroxypentanoic acid. Answer: PHBV

Question 14

Which from following is a first stage in preparation of viscose rayon ?

Accepted Answer

The preparation of viscose rayon involves several steps. In the first stage, cellulose is treated with a concentrated solution of sodium hydroxide ( NaOH ) to form alkali cellulose. The reaction is: Cell - OH + NaOH Cell - ONa + H _2 O In the subsequent stages, the alkali cellulose is reacted with carbon disulfide ( CS _2) to form sodium cellulose xanthate, which is then dissolved in dilute NaOH to form a viscous solution called viscose. Finally, it is extruded into an acid bath to regenerate ce

Question 15

Identify the polymer used to prepare disposable cups and plates.

Accepted Answer

Polystyrene is a synthetic aromatic hydrocarbon polymer made from the monomer styrene. It is widely used in the manufacture of disposable cups, plates, toys, radio and television cabinets, and as a wrapping material. Polypropylene is used for ropes, toys, pipes, and fibres. Polyethylene terephthalate (PET) is used for making bottles and synthetic fibres. High density polyethylene (HDPE) is used for buckets, dustbins, bottles, and pipes. Answer: Polystyrene

Question 16

Which from following polymer is obtained by addition polymerization?

Accepted Answer

Addition polymerization involves the repeated addition of monomer molecules possessing double or triple bonds to form a polymer, without the elimination of any small molecules. Option (322647) represents Polyacrylonitrile (PAN), which is formed by the addition polymerization of acrylonitrile ( CH _2= CH - CN ). Option (322648) represents Nylon-6, which is a condensation polymer of caprolactam. Option (322649) represents Terylene (Dacron), which is a condensation polymer of ethylene glycol and te

Question 17

Which from following polymers is used to obtain articles like rain coats?

Accepted Answer

Polyvinyl chloride (PVC) is a widely used synthetic plastic polymer. It is water-resistant and durable, making it the primary material used in the manufacture of articles like raincoats, hand bags, vinyl flooring, and water pipes. The monomer of PVC is vinyl chloride ( CH _2= CHCl ). Upon polymerization, it forms PVC, which has the repeating unit - [ CH _2 - Cl CH ]_n-. Answer: -\!\! [ CH _2 - Cl CH ]\!\!-_n

Question 18

Which from following is a homopolymer ?

Accepted Answer

A homopolymer is a polymer which is formed from only one type of monomer. Polyacrylonitrile is formed by the addition polymerization of a single monomer, acrylonitrile. Buna-N is a copolymer formed from two different monomers, 1,3-butadiene and acrylonitrile. Urea formaldehyde resin is a condensation copolymer formed from urea and formaldehyde. Polycarbonate is a condensation copolymer typically formed from bisphenol A and phosgene. Therefore, polyacrylonitrile is the only homopolymer among the

Question 19

Which polymer is commonly used in nonstick cookwares ?

Accepted Answer

Teflon (polytetrafluoroethylene) is chemically inert and highly resistant to heat. It has a very low coefficient of friction, which prevents food from sticking to the surface. Therefore, Teflon is commonly used as a coating in nonstick cookware. Answer: Teflon

Question 20

Identify the polymer used to prepare plastic bottles needed to store cooking oil.

Accepted Answer

Polyethylene terephthalate (PET) is a strong, lightweight, and transparent synthetic resin belonging to the polyester family of polymers. It provides an excellent barrier to oxygen and moisture, making it highly suitable for food packaging. PET is widely blow-moulded into disposable plastic bottles used for storing cooking oil, mineral water, and carbonated beverages. Answer: PET

Polymers — Previous Year Questions & Solutions