Tag: chemistry

Questions Related to chemistry

Synthetic fiber does not obtained from renewable resources is : 

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Nylon

  2. Polyester

  3. Rayon

  4. Acrylic

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Correct Option: C
Explanation:

Synthetic fibres are manufactured using plant materials and minerals. 


Viscose comes from pine trees or petrochemicals, while acrylic, nylon and polyester come from oil and coal. 

Viscose fibre is obtained from the cellulose; versatility allows imitating materials such as cotton or silk.

Rayon is a manufactured fiber made from natural sources such as wood and agricultural products that are regenerated as cellulose fiber. 

The many types and grades of rayon can imitate the feel and texture of natural fibers such as silk, wool, cotton, and linen.

Therefore, option C is correct.

Regenerated fibres have superior physical properties because

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. they are fresh fibres

  2. they are obtained naturally

  3. they are chemically treated fibres

  4. None of the abvoe

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Correct Option: C
Explanation:

Regenerated fibre is created by dissolving the cellulose area of plant fibre in chemicals and making it into fibre  again.It consists of cellulose like cotton and hemp  so it is called as regenerated cellulose fibre.

Bakelite is formed by:

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. polymerization of phenol and formaldehyde

  2. polymerization of alcohol and acetaldehyde

  3. condensation of phenol and formaldehyde

  4. condensation of phenol and acetaldehyde

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Correct Option: C
Explanation:

Bakelite is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde.


Hence, option C is correct.

Which of the following monomers are unsuitable for condensation polymerization?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. hydroxy acids

  2. butane-dioic acid and glycol

  3. diamines and dicarboxylic acids

  4. propanoic acid and ethanol

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Correct Option: D
Explanation:

Propanoic acid and ethanol, both are monofunctional monomers $ CH _3-CH _2- OH , CH _3-CH _2COOH$ which are not suitable for a polycondensation reaction to take place because once they combine by condensation polemerisation further polymerisation is not possible.

Which of the following is not correct regarding terylene?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Step - growth polymer

  2. Synthetic fiber

  3. Condensation polymer

  4. Dacron

  5. Thermosetting plastic

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Correct Option: E

Which of the following is an example of condensation polymer?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Teflon

  2. Melamine

  3. Nylon-6

  4. BUNA-S

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Correct Option: B

Which of the following are condensation copolymers ?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Nylon - $6$

  2. Nylon - $6, :6$

  3. Dacron

  4. Glyptal

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Correct Option: B,C,D

Which of the following is a step-growth polymer ?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Polyacrylonitrile

  2. Polyisoprene

  3. Nylon

  4. Polythene

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Correct Option: C
Explanation:

Step-growth polymerization refers to a type of polymerization mechanism in which bi-functional or multifunctional monomers react to form first dimers, then trimers, longer oligomers and eventually long-chain polymers. 


For example, Nylon polymerizes by the step-growth polymerization process in which difunctional monomers containing equal parts of amine and carboxylic acid react so that amides are formed at both ends of each monomer 
Polyacrylonitrile, Polyisoprene and Polythene polymerize by chain-growth polymerization of acrylonitrile, isoprene ($2$-methyl-$1,:3$-butadiene) and ethene, respectively. 

Chain-growth polymerization (or addition polymerization) involves the linking together of molecules incorporating double or triple carbon-carbon bonds.

Polymer formation form monomers starts by:

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. condensation reaction between monomers

  2. conversion of monomer to monomer ions by protons

  3. coordination reaction between monomers

  4. hydrolysis of monomers

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Correct Option: A
Explanation:

Polymerization occurs by a condensation reaction, which is a chemical reaction in which two molecules or moieties (functional groups) combine to form a larger molecule, together with the loss of a small molecule such as water, HCl etc.

Option A is correct.

Nylon is made by

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. polymerization of polymers

  2. polymerization of monomers

  3. condensation co-polymers

  4. hydrolysis of polymer

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Correct Option: C