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1)Choose the packing scheme that gives the highest density of spheres. Simple cu

ID: 497063 • Letter: 1

Question

1)Choose the packing scheme that gives the highest density of spheres.

Simple cubic packing

Trigonal close packing

Hexagonal close packing

Body-centered cubic packing

2)Choose the monomers used to synthesize Teflon.

Adipic acid and hexamethylenediamine

Tetrafluoroethylene

1,3-Butadiene and styrene

Vinyl acetate

3)Vulcanization

Crosslinks polymer chains to improve elasticity

Occurs when plastics are molded into a rigid form with high heat

Breaks long polymer chains into shorter ones

None of the Above

4) Select the general class of compounds you would expect to have the highest boiling point.

Alkanes

Ketones

Alcohols

Ethers

5) Choose the substance with the greatest surface tension.

C9H20

C20H42

C5H12

C12H26

6) Which species below has the strongest intermolecular forces?

CH3CH3

CH3CH2CH2CH3

CH3CH2CH3

CH4

7) What is the strongest intermolecular force present in acetone, (CH3)2CO ?

London forces

Dipole-dipole forces

Ionic bonding

Hydrogen bonding

8) Choose the doping material that will cause silicon to become a n-type semiconductor.

As

C

B

Ga

9) Choose the material that is brittle, a poor thermal conductor, a good thermal insulator, and can withstand high temperatures.

Ceramics

Polymers

Metals

Composites

10) Osmium has a density of 22.6 g/mL. Calculate the radius of an Os atom expected if osmium crystallizes in the face-centered cubic structure.

701 pm

103 pm

135 pm

338 pm

Explanation / Answer

1)Choose the packing scheme that gives the highest density of spheres.

Simple cubic packing

Trigonal close packing

Hexagonal close packing

Body-centered cubic packing

Answer = Hexagonal close packing

2)Choose the monomers used to synthesize Teflon.

Adipic acid and hexamethylenediamine

Tetrafluoroethylene

1,3-Butadiene and styrene

Vinyl acetate

Answer = Tetrafluoroethylene

3)Vulcanization

Crosslinks polymer chains to improve elasticity

Occurs when plastics are molded into a rigid form with high heat

Breaks long polymer chains into shorter ones

None of the Above

Answer = Crosslinks polymer chains to improve elasticity

4) Select the general class of compounds you would expect to have the highest boiling point.

Alkanes

Ketones

Alcohols

Ethers

Answer = Alcohols

5) Choose the substance with the greatest surface tension.

C9H20

C20H42

C5H12

C12H26

Answer = C12H26

6) Which species below has the strongest intermolecular forces?

CH3CH3

CH3CH2CH2CH3

CH3CH2CH3

CH4

Answer = CH3CH2CH2CH3

7) What is the strongest intermolecular force present in acetone, (CH3)2CO ?

London forces

Dipole-dipole forces

Ionic bonding

Hydrogen bonding

Answer = Dipole-dipole forces