Evaluate
Question: Evaluate $\cos \left\{\cos ^{-1}\left(\frac{-\sqrt{3}}{2}\right)+\frac{\pi}{6}\right\}$ Solution: $\cos \left\{\pi-\frac{\pi}{6}+\frac{\pi}{6}\right\}$ [Refer to question 2(ii)] $=\cos \{\pi\}$ $=\cos \left(\frac{\pi}{2}+\frac{\pi}{2}\right)$ $=-1$...
Read More →Out of chain growth polymerisation and step-growth
Question: Out of chain growth polymerisation and step-growth polymerisation, in which type will, you place the following. Solution: In this diagram, two monomers simply and combine to form the polymer by a chain-growth polymerization reaction. Here only monomers react with each other to continue the growing chain....
Read More →Evaluate
Question: Evaluate $\cos \left\{\cos ^{-1}\left(\frac{-\sqrt{3}}{2}\right)+\frac{\pi}{6}\right\}$ Solution: $\cos \left\{\pi-\frac{\pi}{6}+\frac{\pi}{6}\right\}$ [Refer to question 2(ii)] $=\cos \{\pi\}$ $=\cos \left(\frac{\pi}{2}+\frac{\pi}{2}\right)$ $=-1$...
Read More →Identify the type of polymer.
Question: Identify the type of polymer. ABBAAABA Solution: Here the monomers A and B are being joined in a random manner in the same polymer chain. So this is an example of a copolymer. A Copolymer is formed usually when the mixture of two or more unsaturated monomers react....
Read More →Find the principal value of :
Question: Find the principal value of : (i) $\sin ^{-1}\left(\frac{-1}{\sqrt{2}}\right)$ (ii) $\cos ^{-1}\left(\frac{-\sqrt{3}}{2}\right)$ (iii) $\tan ^{-1}(-\sqrt{3})$ (iv) $\sec ^{-1}(-2)$ (v) $\operatorname{cosec}^{-1}(-\sqrt{2})$ (vi) $\cot ^{-1}\left(\frac{-1}{\sqrt{3}}\right)$ Solution: (i) Let $\sin ^{-1}\left(\frac{-1}{\sqrt{2}}\right)=x$ $\Rightarrow-\sin ^{-1}\left(\frac{1}{\sqrt{2}}\right)=x\left[\right.$ Formula: $\left.\sin ^{-1}(-x)=-\sin ^{-1} x\right]$ $\Rightarrow \frac{1}{\sqrt...
Read More →Identify the type of polymer.
Question: Identify the type of polymer. AAAAAA Solution: Here the monomer is A-. Since the same or identical monomer is being repeated to form this above polymer, so this is a homopolymer. (Homo means same or identical)...
Read More →Evaluate the following integral:
Question: Evaluate the following integral: $\int \frac{x^{2}}{\left(x^{2}+4\right)\left(x^{2}+9\right)} d x$ Solution: Denominator is factorised, so let separate the fraction through partial fraction, hence let $\frac{x^{2}}{\left(x^{2}+4\right)\left(x^{2}+9\right)}=\frac{A x+B}{\left(x^{2}+4\right)}+\frac{C x+D}{x^{2}+9} \ldots \ldots(i)$ $\Rightarrow \frac{x^{2}}{\left(x^{2}+4\right)\left(x^{2}+9\right)}=\frac{(A x+B)\left(x^{2}+9\right)+(C x+D)\left(x^{2}+4\right)}{\left(x^{2}+4\right)\left(x...
Read More →Vulcanisation makes rubber
Question: Vulcanisation makes rubber ______________. (i) more elastic (ii) soluble in inorganic solvent (iii) crystalline (iv) more stiff Solution: Option (i) and (iv) are the answers....
Read More →Which of the following polymers
Question: Which of the following polymers have vinylic monomer units? (i) Acrilan (ii) Polystyrene (iii) Nylon (iv) Teflon Solution: Option (i), (ii) and (iv) are the answers....
Read More →Which of the following polymers
Question: Which of the following polymers can have strong intermolecular forces? (i) Nylon (ii) Polystyrene (iii) Rubber (iv) Polyesters Solution: Option (i)Nylon and (iv)Polyestersare the answers....
Read More →Which of the following is an example
Question: Which of the following is an example of a synthetic rubber? (i) Polychloroprene (ii) Polyacrylonitrile (iii) Buna-N (iv) cis-polyisoprene Solution: Option (i) Polychloroprene and (iii) Buna-N are the answers....
Read More →Which of the following monomers
Question: Which of the following monomers form biodegradable polymers? (i) 3-hydroxybutyric acid + 3-hydroxypentanoic acid (ii) Glycine + aminocaproic acid (iii) Ethylene glycol + phthalic acid (iv) Caprolactam Solution: Option (i)3-hydroxybutyric acid + 3-hydroxypentanoic acid and (ii)Glycine + aminocaproic acidare the answers....
Read More →Which of the following polymers are condensation
Question: Which of the following polymers are condensation polymers? (i) Bakelite (ii) Teflon (iii) Butyl rubber (iv) Melamine formaldehyde resin Solution: Option (i)Bakeliteand (iv)Melamine formaldehyde resin are the answers....
Read More →Which of the following are addition
Question: Which of the following are addition polymers? (i) Nylon (ii) Melamine formaldehyde resin (iii) Orlon (iv) Polystyrene Solution: Option (iii)Orlon and (iv)Polystyrene are the answers....
Read More →Which of the following polymers
Question: Which of the following polymers are used as fibre? (i) Polytetrafluoroethane (ii) Polychloroprene (iii) Nylon (iv) Terylene Solution: Option (iii)Nylonand (iv)Terylene are the answers....
Read More →Which of the following polymers are
Question: Which of the following polymers are thermoplastic? (i) Teflon (ii) Natural rubber (iii) Neoprene (iv) Polystyrene Solution: Option (i)Teflon and (iv)Polystyreneare the answers....
Read More →Find the principal value of :
Question: Find the principal value of : (i) $\sin ^{-1}\left(\frac{\sqrt{3}}{2}\right)$ (ii) $\sin ^{-1}\left(\frac{1}{2}\right)$ (iii) $\cos ^{-1}\left(\frac{1}{2}\right)$ (iv) $\tan ^{-1}(1)$ (v) $\tan ^{-1}\left(\frac{1}{\sqrt{3}}\right)$ (vi) $\sec ^{-1}\left(\frac{2}{\sqrt{3}}\right)$ (vii) $\operatorname{cosec}^{-1}(\sqrt{2})$ Solution: Trigonometric Table (i) Let $\sin ^{-1}\left(\frac{\sqrt{3}}{2}\right)=\mathrm{x}$ $\Rightarrow \frac{\sqrt{3}}{2}=\sin x$ [ We know which value of $x$ whe...
Read More →Which of the following are characteristics
Question: Which of the following are characteristics of thermosetting polymers? (i) Heavily branched cross-linked polymers. (ii) Linear slightly branched long-chain molecules. (iii) Become infusible on moulding so cannot be reused. (iv) Soften on heating and harden on cooling, can be reused. Solution: Option (i)Heavily branched cross-linked polymers and (iii) Become infusible on moulding so cannot be reused are the answers....
Read More →Evaluate the following integral:
Question: Evaluate the following integral: $\int \frac{1}{(x-1)(x+1)(x+2)} d x$ Solution: Denominator is factorized, so let separate the fraction through partial fraction, hence let $\frac{1}{(x-1)(x+1)(x+2)}=\frac{A}{(x-1)}+\frac{B}{x+1}+\frac{C}{x+2} \ldots \ldots$(i) $\Rightarrow \frac{1}{(x-1)(x+1)(x+2)}$ $=\frac{A(x+1)(x+2)+B(x-1)(x+2)+C(x-1)(x+1)}{(x-1)(x+1)(x+2)}$ $\Rightarrow 1=A(x+1)(x+2)+B(x-1)(x+2)+C(x-1)(x+1) \ldots \ldots$ (ii) We need to solve for A, B and C. One way to do this is ...
Read More →Which of the following polymers,
Question: Which of the following polymers, need at least one diene monomer for their preparation? (i) Dacron (ii) Buna-S (iii) Neoprene (iv) Novolac Solution: Option (ii) Buna-Sand (iii)Neoprene are the answers....
Read More →Which of the following polymer
Question: Which of the following polymer can be formed by using the following monomer unit? (i) Nylon 6, 6 (ii) Nylon 2-nylon 6 (iii) Melamine polymer (iv) Nylon-6 Solution: Option (iv)Nylon-6 is the answer....
Read More →Prove the following
Question: is a polymer having monomer units ____________. Solution: Option (i) is the answer....
Read More →Which of the following statements is not true
Question: Which of the following statements is not true about low-density polythene? (i) Tough (ii) Hard (iii) Poor conductor of electricity (iv) Highly branched structure Solution: Option (ii)Hardis the answer....
Read More →In which of the following polymers
Question: In which of the following polymers ethylene glycol is one of the monomer units? Solution: Option (i) is the answer....
Read More →Which of the following polymer
Question: Which of the following polymer is biodegradable? Solution: Option (C) is the answer....
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