Problem 79
The monomer used for the manufacture of PVC is obtained by the addition of (a) \(\mathrm{Cl}_{2}\) to ethylene (b) \(\mathrm{Cl}_{2}\) to acetylene (c) HCl to ethylene (d) HCl to acetylene in presence of \(\mathrm{Hg}^{2+}\) salts
Problem 80
Which of the following are condensation polymers? (1) PAN (2) Neoprene (3) polystyrene (4) Poly (ethylene terephthalate) (a) 1 and 4 only (b) 3 and 4 only (c) 2 and 3 only (d) 4 only
Problem 81
The number average molecular mass and mass average molecular mass of a polymer are respectively 30,000 and \(40,000 .\) The poly dispersity index of the polymer is (a) \(<1\) (b) \(>1\) (c) 1 (d) 0
Problem 82
Polymerization using Zeigler-Natta catalysis is advantageous over free radical polymerization because (a) it gives highly branched polymer with a high degree of crystallinity (b) it gives linear polymer molecules permitting stereochemical control (c) it can lead to living polymers via anionic polymerization (d) it permits step reaction polymerization resulting in a highly cross linked polymer
Problem 83
\(\left[\mathrm{NH}\left(\mathrm{CH}_{2}\right) \mathrm{NHCO}\left(\mathrm{CH}_{2}\right)_{4} \mathrm{CO}\right] \mathrm{n}\) is a (a) thermosetting polymer (b) homopolymer (c) co-polymer (d) addition polymer
Problem 84
Bakelite is made from phenol and formaldehyde. The initial reaction between the two compounds is an example of (a) free radical reaction (b) aromatic nucleophilic substitution (c) aromatic electrophilic substitution (d) aldol reaction
Problem 85
Which one of the following monomers gives the polymer neoprene on
polymerization?
(a) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{Cl}\)
(b) \(\mathrm{CCl}_{2}=\mathrm{CCl}_{2}\)
(c)
Problem 86
Which is true about polymers? (1) polymers have low molecular weight (2) polymers have high viscosity (3) polymers scatter light (4) polymers do not carry any charge (a) 1,2 and 3 (b) 1,2 and 4 (c) 2,3 and 4 (d) 1,3 and 4
Problem 88
Which of the following statements is correct about polymers? (1) polymers are substances made up of recurring structural units, each of which can be regarded as derived from a specific compound called a monomer (2) polymers made from a single monomeric species are called homopolymers, whereas, those made up of two or more different monomeric species are called copolymers. (3) very often, polymers are macromolecules, and a sample of a given polymer is characteristically a mixture of molecules with different molecular weights (a) 1 and 2 only (b) 1 and 3 only (c) 1,2 and 3 (d) 2 only
Problem 89
Which is correct about Gutta parcha rubber? (1) a very hard material (2) a synthetic polymer (3) a trans 1,4 -polyisoprene polymer (a) 2 only (b) 3 only (c) 1 and 3 only (d) 1,2 and 3
