Match the polymer of column I with
Question: Match the polymer of column I with a correct monomer of column II. Solution: (i) is e (ii) is c (iii) is a (iv) is b (v) is d...
Read More →Why should the monomers use also polymerisation
Question: Why should the monomers use also polymerisation through free radical pathway be very pure? Solution: Pure monomers are used besides polymerization through free radical pathway because even the traces of impurities act as inhibitors and leads to the sudden termination of chain reaction and forms small length polymers....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\sec ^{-1}\left(\frac{-2}{\sqrt{3}}\right)$ Solution: $\sec ^{-1}\left(\frac{-2}{\sqrt{3}}\right)=\pi-\sec ^{-1}\left(\frac{2}{\sqrt{3}}\right)\left[\right.$ Formula: $\left.\sec ^{-1}(-x)=\pi-\sec ^{-1}(x)\right]$ $=\pi-\frac{\pi}{6}$ $=\frac{5 \pi}{6}$...
Read More →Which type of biomolecules has some structural
Question: Which type of biomolecules has some structural similarity with synthetic polyamides? What is this similarity? Solution: Proteins have some structural similarity with synthetic polyamides. Polyamides like Nylon is formed by the combination of Glycine and aminocaproic acid molecule through an amide linkage. Similar amide linkage is present in protein also when two amino acids join with each other....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\tan ^{-1}(-\sqrt{3})$ Solution: $\tan ^{-1}(-\sqrt{3})=-\tan ^{-1}(\sqrt{3})\left[\right.$ Formula: $\left.\tan ^{-1}(-x)=-\tan ^{-1}(x)\right]$ $=-\frac{\pi}{3}$...
Read More →Name the polymers used in laminated
Question: Name the polymers used in laminated sheets and give the name of monomeric units involved in its formation. Solution: Urea-formaldehyde resin is used in laminated sheets. For the formation of laminated sheets, urea and formaldehyde are the monomeric units....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\cot ^{1}(-1)$ Solution: $\cot ^{-1}(-1)=\pi-\cot ^{-1}(1)\left[\right.$ Formula: $\left.\cot ^{-1}(-x)=\pi-\cot ^{-1}(x)\right]$ $=\pi-\frac{\pi}{4}$ $=\frac{3 \pi}{4}$...
Read More →Which factor imparts crystalline nature
Question: Which factor imparts crystalline nature to a polymer like nylon? Solution: One molecule of Nylon can join another by intermolecular H bonding which is present between two terminal groups C=O and NH. Since intermolecular H bonding is relatively strong, it can lead to close packing of chains that impacts the crystalline character of Nylon....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\operatorname{cosec}^{-1}(-\sqrt{2})$ Solution: $\operatorname{cosec}^{-1}(-\sqrt{2})=-\operatorname{cosec}^{-1}(\sqrt{2})\left[\right.$ Formula: $\left.\operatorname{cosec}^{-1}(-x)=-\operatorname{cosec}^{-1}(x)\right]$ $=-\frac{\pi}{4}$ This can also be solved as $\operatorname{cosec}^{-1}(-\sqrt{2})$ Since cosec is negative in the third quadrant, the angle we are looking for will be in the third quadrant. $=\pi+\frac{\pi}{4}$ $=\f...
Read More →What is the role of benzoyl peroxide also polymerisation
Question: What is the role of benzoyl peroxide also polymerisation of alkenes? Explain its mode of action with the help of an example. Solution: Benzoyl peroxide helps to generate free radical in chain initiation step which is the first step of the reaction in the Addition polymerization reaction. Thus it acts as a free radical generating initiator catalyst....
Read More →What is the structural difference between HDP
Question: What is the structural difference between HDP and LDP? How does the structure account for different behaviour and nature, hence the use of a polymer? Solution: HDP is a high-density polymer which has a linear structure and LDP is a low density structure which has branched structure. HDP is chemically inert and has a higher melting point whereas LDP is a lower melting point and flexible....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\sec ^{-1}(-2)$ Solution: $\sec ^{-1}(-2)=\pi-\sec ^{-1}(2)\left[\right.$ Formula: $\left.\sec ^{-1}(-x)=\pi-\sec ^{-1}(x)\right]$ $=\pi-\frac{\pi}{3}$ $=\frac{2 \pi}{3}$...
Read More →Why does cis-polyisoprene possess
Question: Why does cis-polyisoprene possess elastic property? Solution: Due to the presence of these weak forces the polymer can be stretched by applying force. The polymer returns to its original state as soon as the external force is removed, thus exhibiting elastic property....
Read More →To have practical applications
Question: To have practical applications why are cross-links required in rubber? Solution: To improve these physical properties, cross-linking is done which helps to bind its planar polymer sheets thus increasing elastomeric properties, thermal stability....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\tan ^{-1}(-1)$ Solution: $\tan (-1)=-\tan (1)$ [ Formula: $\tan ^{-1}(-x)=-\tan ^{-1}(x)$ ] [We know that $\tan \frac{\pi}{4}=1$, thus $\tan ^{-1} \frac{\pi}{4}=1$ ] $=-\frac{\pi}{4}$...
Read More →How is the following resin intermediate
Question: How is the following resin intermediate prepared and which polymer is formed by this monomer unit? Solution: Melamine and formaldehyde are the two starting monomers for this Resin intermediate. Their condensed polymerisation gives melamine polymer....
Read More →Evaluate the following integral:
Question: Evaluate the following integral: $\int \frac{5 x^{2}-1}{x(x-1)(x+1)} d x$ Solution: Denominator is factorized, so let separate the fraction through partial fraction, hence let $\frac{5 x^{2}-1}{x(x-1)(x+1)}=\frac{A}{x}+\frac{B}{x-1}+\frac{C}{x+1} \ldots \ldots$ (i) $\Rightarrow \frac{5 x^{2}-1}{x(x-1)(x+1)}=\frac{A(x-1)(x+1)+B x(x+1)+C x(x-1)}{x(x-1)(x+1)}$ $\Rightarrow 5 x^{2}-1=A(x-1)(x+1)+B x(x+1)+C x(x-1) \ldots \ldots .($ ii $)$ We need to solve for A, B and C. One way to do this ...
Read More →Can nucleic acids, proteins and starch
Question: Can nucleic acids, proteins and starch be considered as step growth polymers? Solution: Nucleic acids, proteins and starch can be considered as step-growth polymers. Step growth polymers are condensation polymers. Monomers which possess bifunctional or trifunctional functional groups can combine by the loss of a simple molecule...
Read More →Can the enzyme be called a polymer?
Question: Can the enzyme be called a polymer? Solution: The enzyme acts as a catalyst which enhances the biological reactions. They are made up of proteins. Proteins are the polymers having monomeric unit known as amino acids. Thus, enzymes are also polymers....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\cos ^{-1}\left(\frac{-1}{2}\right)$ Solution: $\cos ^{-1}\left(\frac{-1}{2}\right)=\pi-\cos ^{-1}\left(\frac{1}{2}\right)\left[\right.$ Formula: $\left.\cos ^{-1}(-x)=-\cos ^{-1}(x)\right]$ $=\pi-\frac{\pi}{3}$ $=\frac{2 \pi}{3}$...
Read More →Why are rubbers called elastomers?
Question: Why are rubbers called elastomers? Solution: Rubbers can be stretched by applying force and come back to its original form after the removal of applied force. So they are called elastomers....
Read More →Identify the polymer given below :
Question: Identify the polymer given below : Solution: This is polyisoprene or natural rubber. The monomeric unit of this polymer is 2-methyl-1,3-butadiene....
Read More →Find the principal value of each of the following :
Question: Find the principal value of each of the following : $\sin ^{-1}\left(\frac{-1}{2}\right)$ Solution: $\sin ^{-1}\left(\frac{-1}{2}\right)=-\sin ^{-1}\left(\frac{1}{2}\right)$ [Formula: $\sin ^{-1}(-x)=\sin ^{-1}(x)$ ] $=-\frac{\pi}{6}$...
Read More →Evaluate
Question: Evaluate $\sin \left\{\frac{\pi}{2}-\left(\frac{-\pi}{3}\right)\right\}$ Solution: $\sin \left(\frac{\pi}{2}+\frac{\pi}{3}\right)$ $=\sin \left(\frac{5 \pi}{6}\right)$ $=\sin \left(\pi-\frac{\pi}{6}\right)$ $=\sin \frac{\pi}{6}$ $=\frac{1}{2}$...
Read More →Identify the type of polymer
Question: Identify the type of polymer given in the following figure. Solution: This is a cross-linked or Network polymer. Two linear polymers are joined by cross-linking....
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