141. Which of the following polymers do not involve cross linkages ?
A
Melmac
B
Bakelite
C
Polythene
D
Vulcanised rubber
Answer :
Polythene
142. Among cellulose, polyvinyl chloride, nylon and natural rubber, the polymer in which the intermolecular force of attraction is weakest is
A
nylon
B
polyvinyl chloride
C
cellulose
D
natural rubber
Answer :
natural rubber
143. Synthetic polymer prepared by using caprolactam is known as
A
terylene
B
teflon
C
nylon 6
D
neoprene
Answer :
nylon 6
144. Which of the following polymers is not correctly matched?
A
Formation of dacron - Step growth polymerisation
B
Formation of polytetrafluoroethene - Step growth polymerisation
C
Formation of polythene - Chain growth polymerisation in presence of benzoyl peroxide
D
Formation of polyacrylonitrile - Chain growth polymerisation in presence of peroxide
Answer :
Formation of polytetrafluoroethene - Step growth polymerisation
145. Which among the following is a cross-linked polymer?
A
Polyesters
B
Glycogens
C
Melamine-formaldehyde
D
Polyvinyl chloride
Answer :
Melamine-formaldehyde
146. Buna - $$ N$$ synthetic rubber is a copolymer of :
A
$${H_2}C = CH - CH = C{H_2}\,\,{\text{and}}$$ $${H_5}{C_6} - CH = C{H_2}$$
B
$${H_2}C = CH - CN\,\,{\text{and}}$$ $${H_2}C = CH - CHC{H_2}$$
C
$${H_2}C = CH - CN\,\,{\text{and}}$$ \[{{H}_{2}}C=CH\underset{\begin{smallmatrix}
|\,\,\, \\
\,C{{H}_{3}}
\end{smallmatrix}}{\mathop{-C=}}\,C{{H}_{2}}\]
D
\[{{H}_{2}}C=CH\overset{\begin{smallmatrix}
\,Cl \\
|
\end{smallmatrix}}{\mathop{-C=}}\,C{{H}_{2}}\,\,\text{and}\] $${H_2}C = CH - CH = C{H_2}$$
Answer :
$${H_2}C = CH - CN\,\,{\text{and}}$$ $${H_2}C = CH - CHC{H_2}$$
147. Few polymers are matched with their uses. Point out the wrong match.
A
Polyesters - Fabric, tyre cords, safety belts
B
Nylon 6 - Ropes, tyre cords, fabrics
C
Bakelite - Packaging industry, lubricant
D
Teflon - Oil seals, gaskets, non-stick utensils
Answer :
Bakelite - Packaging industry, lubricant
148. Which of the following polymers does not involve cross-linkages?
A
Vulcanised rubber
B
Bakelite
C
Melamine
D
Teflon
Answer :
Teflon
149. Which of the following is not correctly matched?
A
B
C
D
Answer :
150. Polydispersity index $$(PDI)$$ is
A
$$\frac{{{{\bar M}_w}}}{{{{\bar M}_n}}}$$
B
$$\frac{{{{\bar M}_n}}}{{{{\bar M}_w}}}$$
C
$${{\bar M}_n} \times {{\bar M}_w}$$
D
$${{\bar M}_w} - {{\bar M}_n}$$
Answer :
$$\frac{{{{\bar M}_w}}}{{{{\bar M}_n}}}$$