Class 12th

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 Long Answer Type Questions as classified in NCERT Exemplar

Sol:

$\begin{array}{l}Let\text{?}\text{?}\text{?}\text{?}I={\displaystyle ?\underset{II}{e^{?3x}}}\underset{I}{co{s}^{3}x}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=co{s}^{3}x.{\displaystyle ?e^{?3x}\text{?}dx}?{\displaystyle ?\left(D\left(co{s}^{3}x\right).{\displaystyle ?e^{?3x}\text{?}dx}\right)dx}\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=co{s}^{3}x.\frac{e^{?3x}}{?3}?{\displaystyle ?\left(3co{s}^{2}x\left(?sinx\right).\frac{e^{?3x}}{?3}\right)dx}\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?{\displaystyle ?co{s}^{2}xsinx.}{e}^{?3x}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?{\displaystyle ?\left(1?si{n}^{2}x\right)sinx.}{e}^{?3x}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?{\displaystyle ?sinx.e^{?3x}dx}+{\displaystyle ?\underset{I}{si{n}^{3}x}}.\underset{II}{e^{?3x}}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?{\displaystyle ?sinx.e^{?3x}dx}+si{n}^{3}x{\displaystyle ?e^{?3x}dx?{\displaystyle ?\left(D\left(si{n}^{3}x\right).{\displaystyle ?e^{?3x}\text{?}dx}\right)dx}}\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?{\displaystyle ?sinx.e^{?3x}dx}+si{n}^{3}x.\frac{e^{?3x}}{?3}?{\displaystyle ?\left(3si{n}^{2}x.cosx.\frac{e^{?3x}}{?3}\right)dx}\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?{\displaystyle ?sinx.e^{?3x}dx}?\frac{1}{3}{e}^{?3x}si{n}^{3}x+{\displaystyle ?si{n}^{2}xcosx.}{e}^{?3x}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?{\displaystyle ?sinx.e^{?3x}dx}?\frac{1}{3}{e}^{?3x}si{n}^{3}x+{\displaystyle ?\left(1?co{s}^{2}x\right)cosx.}{e}^{?3x}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}I=?\frac{1}{3}{e}^{?3x}co{s}^{3}x?\left[sinx.\frac{e^{?3x}}{?3}?{\displaystyle ?cosx.\frac{e^{?3x}}{?3}dx}\right]?\frac{1}{3}{e}^{?3x}si{n}^{3}x+{\displaystyle ?cosx.e^{?3x}}dx?{\displaystyle ?co{s}^{3}x.e^{?3x}dx}\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=?\frac{1}{3}{e}^{?3x}co{s}^{3}x+sinx.\frac{e^{?3x}}{3}?{\displaystyle ?cosx.\frac{e^{?3x}}{?3}dx}?\frac{1}{3}{e}^{?3x}si{n}^{3}x+{\displaystyle ?cosx.e^{?3x}}dx?I\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}2I=\frac{e^{?3x}}{?3}\left[co{s}^{3}x+si{n}^{3}x\right]?\left[sinx.\frac{e^{?3x}}{3}?{\displaystyle ?cosx.\frac{e^{?3x}}{?3}dx}\right]+{\displaystyle ?cosx.e^{?3x}}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=\frac{e^{?3x}}{?3}\left[co{s}^{3}x+si{n}^{3}x\right]+\frac{1}{3}sinx.e^{?3x}?\frac{1}{3}{\displaystyle ?cosx.e^{?3x}}dx+{\displaystyle ?cosx.e^{?3x}}dx\\ ?\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}2I=\frac{e^{?3x}}{?3}\left[co{s}^{3}x+si{n}^{3}x\right]+\frac{1}{3}sinx.e^{?3x}+\frac{2}{3}{\displaystyle ?cosx.e^{?3x}}dx\\ Now,\text{?}{I}_1=\frac{2}{3}{\displaystyle ?\underset{I}{cosx}}.\underset{II}{e^{?3x}}dx\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=\frac{2}{3}\left[cosx.{\displaystyle ?e^{?3x}dx}?{\displaystyle ?\left(D\left(cosx\right).{\displaystyle ?e^{?3x}\text{?}dx}\right)dx}\right]\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=\frac{2}{3}\left[cosx.\frac{e^{?3x}}{?3}?{\displaystyle ??sinx.\frac{e^{?3x}}{?3}dx}\right]\\ \text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}\text{?}=\frac{2}{3}\left[cosx.\frac{e^{?3x}}{?3}?\frac{1}{3}{\displaystyle ?sinx.e^{?3x}dx}\right]\end{array}$