Question 1

Which of the following are characteristic of linear polyethylene?
A)They are branched polymers.
B)They are known as high-density polyethylene.
C)They are soft and flexible polymers.
D)A and B
E)A and C

Accepted Answer

Linear polyethylene is known as high-density polyethylene because of its tightly packed molecular structure. It is not branched and not soft and flexible, unlike low-density polyethylene.

Question 2

Which of the following statements best explains the process known as chain transfer?
A)a process that can control the rate of production of the polymer
B)a process that can control the molecular weight of the polymer
C)a process that can control the reactivity of the monomer
D)a process that can slow down the polymerization reaction
E)a process that can inhibit the polymerization reaction

Accepted Answer

Chain transfer is a process where a reactive intermediate reacts with a third molecule, transferring the growing polymer chain to it. This can result in the formation of a new reactive species and can affect the molecular weight of the polymer.

Question 3

What is the structure of the monomer from which the following polymer is made? A)CH₃CH₃ B)CH₂ CH₂ C)CH₃CH CH₂ D)CH₂ CHCH CH₂ E)CH₃CH CHCH₃

Accepted Answer

E

Question 4

Which of the following is the first chain propagating step in the radical polymerization of ethylene? A)ROOR + CH₂ CH₂ → ROCH₂CH₂OR B) ∙ RO∙ + CH₂ CH₂ → ROCH₂CH₂ C)RO∙ + CH₂ CH₂ → ROCH CH₂ + H∙ D) ∙ ∙ ROOR + CH₂ CH₂ → 2 ROH + CH CH E) ∙ ∙ 2RO∙ + CH₂ CH₂ → 2 ROH + CH CH

Accepted Answer

The first chain propagating step in the radical polymerization of ethylene involves the reaction between a radical initiator (RO∙) and ethylene (CH2=CH2), forming a new radical on the ethylene molecule (CH2=CH∙). Therefore, the correct option is B, which shows the reaction between RO∙ and CH2=CH2, forming CH2=CH∙. The other options show different reactions, such as termination, initiation or hydrogen abstraction, which are not the first chain propagating step in the radical polymerization of ethylene.

Question 5

Which of the following species can best serve as an initiator for anionic polymerization? A)CH₃CH₂CH₂CH₂Li B)BF₃ C)HOOH D)CH₃CH₂CH₂CH₂OH E)CH₃CH₂CH₂CH₂OCH₂CH₂CH₂CH₃

Accepted Answer

The species CH₃CH₂CH₂CH₂Li is a strong initiator for anionic polymerization due to the presence of the lithium ion, which can act as a strong electron acceptor and activate the monomer. The other choices are not suitable initiators for anionic polymerization.

Question 6

Which of the following is the chain-initiating step in the cationic polymerization of propene? 
A)I
B)II
C)III
D)IV
E)V

Accepted Answer

The answer of Which of the following is the chain-initiating...

Question 7

Chain-growth polymerization exhibits a marked preference for ________.
A)tail-to-tail addition
B)head-to-head addition
C)head-to-tail addition
D)head-to-middle addition
E)middle-to-tail addition

Accepted Answer

Chain-growth polymerization typically involves the addition of a monomer to the end of the growing polymer chain, which results in a head-to-tail addition. This is the most thermodynamically favorable orientation for the monomer due to the stabilizing interactions between the newly added monomer unit and the previously added units. Therefore, head-to-tail addition is the marked preference for chain-growth polymerization.

Question 8

Which of the following monomers has the greatest ability to undergo cationic polymerization? 
A)I
B)II
C)III
D)IV
E)V

Accepted Answer

The answer of Which of the following monomers has the...

Question 9

Which of the following species can best serve as an initiator for cationic polymerization? A)ROOR B)ROH C)ROR D)AlCl₃ E)RCOOR

Accepted Answer

AlCl3 is a strong Lewis acid and can effectively initiate cationic polymerization by generating a carbocationic species that propagates the polymer chain.

Question 10

Draw the structure of the polymer and by-product that result when the two monomers below are heated together.

Accepted Answer

The answer of Draw the structure of the polymer and...

Question 11

Chain-growth polymerization proceeds by which of the following mechanisms?
A)radical polymerization
B)cationic polymerization
C)anionic polymerization
D)A and B
E)A, B, and C

Accepted Answer

Chain-growth polymerization can proceed through radical, cationic, or anionic mechanisms, all of which involve the growth of a polymer chain by the successive addition of monomer units to an active site on the growing chain.

Question 12

The choice of mechanism in chain-growth polymerization depends on which of the following?
A)structure of the monomer and initiator used
B)structure of the polymer and initiator used
C)temperature and pressure of the reaction
D)A and B
E)A, B, and C

Accepted Answer

The answer of The choice of mechanism in chain-growth polymerization...

Question 13

Which of the following is more likely to undergo both radical and cationic polymerization? 
A)I
B)II
C)III
D)IV
E)V

Accepted Answer

The answer of Which of the following is more likely...

Question 14

Which of the following addition polymers results from the reaction below? nCF₂ CF₂ _? A)[ CF-CF ]_n B)[CF₃-CF₃]_n C)[-CF₂-CH CHCF₂-]_n D)[-CF₂-CF₂-]_n E)[-CF₂ CF₂-]_n

Accepted Answer

The addition polymer that results from the given reaction has the repeating unit -CFS1U1B12-. The correct choice is D, which shows this repeating unit twice with the linkage -S1U1B0- between them and a terminal -S1U1B1- group. The other choices show different monomers and/or different linkages, and are hence incorrect.

Question 15

List the two major classes of synthetic polymers and give one example of each.

Accepted Answer

The answer of List the two major classes of synthetic...

Question 16

Which of the following species can best serve as a radical initiator for radical polymerization?
A)ROH
B)ROR
C)ROOR
D)RCOOR
E)RCOOH

Accepted Answer

ROOR is a peroxide that can easily break down into two radicals, initiating radical polymerization. The other options (ROH, ROR, RCOOR, RCOOH) are not as effective in generating radicals.

Question 17

What is the structure of the monomer from which the following polymer is made?  
A)I
B)II
C)III
D)IV
E)V

Accepted Answer

The answer of What is the structure of the monomer...

Question 18

Which of the following statements best describes what alpha olefins are?
A)polysubstituted ethylenes
B)monosubstituted ethylenes
C)disubstituted ethylenes
D)ethylenes
E)isoprenes

Accepted Answer

Alpha olefins are monosubstituted ethylenes, meaning that they have one substituent (group of atoms) attached to the double bond in the ethylene molecule.

Question 19

Which of the following monomers has the greatest ability to undergo anionic polymerization? 
A)I
B)II
C)III
D)IV
E)V

Accepted Answer

The answer of Which of the following monomers has the...

Question 20

Which of the following is a possible step to terminate a chain in the radical polymerization of ethylene? A)ROOR + CH₂ CH₂ → ROCH₂CH₂OR B)CH₂ CH₂ + CH₂ CH₂ → CH₃CH CHCH₃ C) ∙ RO∙ + CH₂ CH₂ → ROCH₂ CH₂ D) ∙ ∙ ROCH₂CH₂ + CH₂ CH₂ → ROCH₂CH₂CH₂CH₂ E) ∙ 2 RO-[CH₂CH₂]_n-CH₂CH₂ → RO-[CH₂CH₂]_n-CH₂CH₂CH₂CH₂-[CH₂CH₂]_n-OR

Accepted Answer

The answer of Which of the following is a possible...

Quiz 27: Synthetic Polymers

Which of the following are characteristic of linear polyethylene?

Which of the following statements best explains the process known as chain transfer?

What is the structure of the monomer from which the following polymer is made?

Which of the following is the first chain propagating step in the radical polymerization of ethylene?

Which of the following species can best serve as an initiator for anionic polymerization?

Which of the following is the chain-initiating step in the cationic polymerization of propene?

Chain-growth polymerization exhibits a marked preference for ________.

Which of the following monomers has the greatest ability to undergo cationic polymerization?

Which of the following species can best serve as an initiator for cationic polymerization?

Draw the structure of the polymer and by-product that result when the two monomers below are heated together.

Chain-growth polymerization proceeds by which of the following mechanisms?

The choice of mechanism in chain-growth polymerization depends on which of the following?

Which of the following is more likely to undergo both radical and cationic polymerization?

Which of the following addition polymers results from the reaction below? nCF2 CF2 ?

List the two major classes of synthetic polymers and give one example of each.

Which of the following species can best serve as a radical initiator for radical polymerization?

What is the structure of the monomer from which the following polymer is made?

Which of the following statements best describes what alpha olefins are?

Which of the following monomers has the greatest ability to undergo anionic polymerization?

Which of the following is a possible step to terminate a chain in the radical polymerization of ethylene?

Which of the following addition polymers results from the reaction below? nCF₂ CF₂ _?