Question 1

How are HDPE and LDPE different?

Accepted Answer

HDPE has a linear structure, whereas LDPE has a branched structure. This difference in structure affects the physical properties of the two polymers, such as their strength, flexibility, and density.

Question 2

Which of these polymers is made by the process of condensation polymerization?

Accepted Answer

Polyethylene terephthalate (PET) is made by the process of condensation polymerization. The reactions that form PET involve the elimination of a small molecule, such as water or methanol, in order to form the polymer chain. The other options, Polyethylene, Polystyrene, and Polyvinylchloride are made by addition polymerization, where monomers are added together to form the polymer chain.

Question 3

Which is an amine group?

Accepted Answer

The amine group is represented by -NH2, which is option B. The notation "₂" seems to be a formatting or encoding error, but the correct answer is the one that includes -NH, indicating an amine group.

Question 4

Which equation below shows the addition polymerization of ethylene?

Accepted Answer

The addition polymerization of ethylene involves the repeated addition of monomers, with no elimination of any by-product. Therefore, the correct equation must show a long chain of repeating monomer units. Choice B shows the repeating unit (-CH2-CH2-)n, which represents the addition polymerization of ethylene.

Question 5

What do the "big six" polymers have in common?

Accepted Answer

The "big six" polymers, which include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, and polymethyl methacrylate, are all thermoplastics. This means that they can be melted and shaped repeatedly without losing their inherent properties. Additionally, they are all formed by addition polymerization. While some of them may contain branched chains, this is not a universal characteristic shared by all of them.  Therefore, option C is the best choice.

Question 6

A polymer that is made from two different monomers is known as a

Accepted Answer

A polymer that is made from two different monomers is known as a copolymer. A dimer refers to a molecule composed of two identical subunits, while dipolymer and multimer are not commonly used terms in polymer science.

Question 7

Which of these statements are correct for condensation polymerization only?
i.Monomer units chemically bond together
ii.Product contains all the atoms of the starting material
iii.A second product,like water,is also formed during the polymerization process

Accepted Answer

In condensation polymerization, monomer units chemically bond together to form a polymer, so statement i is correct. Also, a second product, like water, is formed during the polymerization process due to the elimination of a small molecule, so statement iii is also correct. However, the product of condensation polymerization doesn't contain all the atoms of the starting material because a small molecule is lost during the polymerization process, so statement ii is incorrect. Therefore, the correct choice is D, i and iii.

Question 8

Which bond represents the peptide bond?

Accepted Answer

The peptide bond is a type of covalent bond between the carboxyl group of one amino acid and the amino group of another amino acid in a polypeptide chain. This bond is represented by the bond labeled II, which is a covalent bond between the carbon atom of the carboxyl group and the nitrogen atom of the amino group.

Question 9

Which of these represents a portion of a polyester molecule?

Accepted Answer

The answer of Which of these represents a portion of...

Question 10

Which of these statements are correct for addition polymerization only?
i.Monomer units chemically bond together
ii.Product contains all the atoms of the starting material
iii.There is generally just one monomer

Accepted Answer

In addition polymerization, monomer units chemically bond together (i) and the product contains all the atoms of the starting material (ii). There is generally just one monomer (iii) is not exclusive to addition polymerization.

Question 11

Which of these statements are correct for both addition and condensation polymerization?
i.Monomer units chemically bond together
ii.Product contains all the atoms of the starting material
iii.A second product,like water,is also formed during the polymerization process

Accepted Answer

In both addition and condensation polymerization, monomer units chemically bond together to form polymers. However, in addition polymerization, the product contains all the atoms of the starting material (no small molecules are lost), whereas in condensation polymerization, a small molecule (often water) is also formed as a byproduct.

Question 12

Which equation correctly shows the first step in the formation of polyethylene terephthalate (PET) by the process of condensation polymerization?

Accepted Answer

The answer of Which equation correctly shows the first step...

Question 13

These are the two monomers used to synthesize Kevlar.  Which of the following represent the products formed after one condensation reaction between the monomers?

Accepted Answer

The answer of These are the two monomers used to...

Question 14

How many carbon atoms are present in this monomer?

Accepted Answer

The answer of How many carbon atoms are present in...

Question 15

In this molecule four different functional groups are circled.  Which is the carboxylic acid functional group?

Accepted Answer

The carboxylic acid functional group is characterized by a carbonyl group (C=O) and a hydroxyl group (OH) attached to the same carbon atom. This functional group is present in option III, which has a carboxylic acid group (-COOH) attached to a benzene ring.

Question 16

Polyvinyl chloride (PVC) is made from the monomer,CH₂ CHCl.Which would not be a possible arrangement in PVC?

Accepted Answer

The answer of Polyvinyl chloride (PVC) is made from the...

Question 17

What do the letters HDPE represent?

Accepted Answer

HDPE stands for High density polyethylene.

Question 18

Consider the process of condensation polymerization.Which statement is false?

Accepted Answer

In condensation polymerization, a small molecule, often water, is eliminated as the monomers link together, meaning the final polymer does not contain all the atoms of the starting materials.

Question 19

Dacron is classified as a polyester.Which linkage is correct? (The gray areas represent the monomer backbones. )

Accepted Answer

The answer of Dacron is classified as a polyester.Which linkage...

Question 20

Which of these represents an amino acid?

Accepted Answer

The answer of Which of these represents an amino acid?
...

Quiz 9: The World of Polymers and Plastics