Exam one

The name of the polymer formed from CH₂=CH₂ is

polyethylene

The IUPAC designation of the polymer \_\/^o\_n is:

poly(oxymethylene)

In general, which of the following polymers cannot be recycled?

thermosets

The monomer of natural rubber is

isoprene

2 methyl-1 propane

The segment (\_|/)\_|/ represents the polymer named

polypropylene

The monomer used to form the polymer shown below is..

-(CH(OH)-CH₂-CH(OH)-CH(OH)-CH₂-)CH₃

CH₂ = CHOH

Dispersion force’s interaction energy is proportional to (take “r” as the distance between the two particles)___

1/r⁶

Dipole-Dipole forces are stronger than__ and weaker than___ interactions

London, ion-ion

Which of the following interaction occurs between a permanent dipole and a neutral molecule?

Dipole-induced dipole interactions

Polyethylene and polypropylene (in the melt) will

only interact weakly through dispersion forces

Thermosetting plastic materials

Cannot be melted after forming

Which of these choices is not an intermolecular force that affects the structure of a polymer?

adhesive force

Which of the following copolymers is the copolymer with regular alternating A and B units?

alternating copolymer

Which of the following copolymers is the copolymer in which the main chain is formed from one type of monomer A and branches are formed from another monomer B?

Graft copolymer

Which pattern of the following is not a copolymer

AAAAAAAAAAAAAA

Consider the following copolymers, which of these is a triblock copolymer?

(B-B-B—-B-B)(A-A-A—-A-A)(B-B—B-B-B)

What term is used to describe the relative arrangements of chiral carbon atoms within a polymer?

Tacticity

Consider the molecular weight distribution shown below. The average indicated by (a) is

the number average molecular weight

The average indicated as (b) in the above figure is most likely the

the weight averaged molecular weight

The ratio of Mw and Mn for the most synthetic polymers is:

>1

The molecular weight of a polymer is equal to the molecular weight of the repeat unit multiplied by the degree of polymerization. What is the molecular weight of polyvinyl chloride (PVC), if its degree of polymerization is 800? (Atomic weight of Cl:35.453 g/mol, C:12.011 g/mol, H:1.0079g/mol

-CH₂-CHCl

50000

A polystyrene has a number average molecular weight of 100,000 g/mol and a polydispersity of 5. What is the weight average molecular weight in g/mol?

PDI = Mw/Mn

20,000

Normal poly(methylmethacrylate) is atactic. This means that

the methyl groups alternate randomly back and forth along the backbone

The segment of a polypropylene chain shown below suggests that this polymer is:

syndiotactic

When non-symmetrical alkenes polymerize (such as chloroethene- which makes up PVC), there are 3 ways in which the groups can be arranged in 3-d space. For example, if all the -Cl groups in polychloroethene (PVC) were arranged in the same direction in 3-D space, the polymer would be described as isotactic. What term is used to describe a polymer where the groups are arranged randomly?

atactic

An NMR analysis of a polystyrene sample showed that it had close to 100% racemic diads. The sample would be

atactic polystyrene

An NMR analysis of a polystyrene sample showed that it had about 50% meso diads and 50% racemic diads. The sample would be

atactic polystyrene

Atactic polymers are:

low melting and easily soluble

In a linear polymer, the monomeric units are linked together to form long straight chains. The cross-linked or branched chain polymers compared to linear polymers have higher

hardness, rigidity & brittleness

Which of the following statements best describes the second law of thermodynamics

when an isolated system undergoes a spontaneous change, the entropy of the system will increase

The first law of thermodynamics deals with

conservation of energy

The equation of the first law of thermodynamics is

internal energy= heat added plus work done

Entropy occurs due to

change in macroscopic variables

What is the equation of entropy?

The ratio of reversible transfer of heat to absolute temperature

The absolute thermodynamic temperature scale is also known as

kelvin scale

If liquids A and B form an ideal solution, then what is the Gibbs free energy of mixing?

=0

What is not true about Flory Huggin’s Theory?

the advantage is that it is a simple equation