Unit 4 Quiz

Chemcom Unit 4 Exam . . . Petroleum: Breaking and Making Bonds

True/False (Choose the best answer.)

Refined petroleum is the world's major source of hydrocarbons.
In the Separation by Distillation Lab, hydrocarbons were separated by their difference in densities.
When petroleum is refined, it is separated into compounds with different molecular size.
Smaller molecules tend to have smaller intermolecular forces and smaller boiling points.
Electrons are organized into "shells" in the atom and the first shell holds 8 electrons.
Fluorine is in the 7th column of the periodic table and has an electron dot picture equal to
An electron dot picture for the molecule HF would be
The structural formula for HF is H-F.
Alkanes are hydrocarbons that are made up of only single bonds.
The molecules CH₃CH₂CH₃ and CH₃CH₂CH₂CH₃ are isomers of each other.
Endothermic reactions give off energy and feel warm to the touch.
Given the conversion factors and , 8.3 gallons of gasoline are used in one week.
In automobiles most of the energy you purchase as gasoline is used to make the car move.
As the size of the hydrocarbon molecule increases, it gives more energy per gram when burned for fuel.
Methane produces 890 Kilojoules of energy per mole. One mole of methane is 16 grams. 32 grams of methane would give 28 KJ of energy.
The term cracking refers to breaking large hydrocarbons into smaller hydrocarbons that are more useful.
The octane rating of a fuel can be increased by using oxygenated fuels, adding MTBE, or blending branched chain alkanes with the fuel.
Engine "knocking" or "pinging" results from fuels that have low energy values per gram.
Monomers are small hydrocarbons that can be joined together to form polymers.
Alkenes are hydrocarbons that contain double bonds and alkynes are hydrocarbons that contain triple bonds
CH₂=CH-CH₃ and CH₃-CH=CH₂ are isomers of each other.
CH₃OH is an example of an alcohol.
Alcohols ( R₁-OH ) and carboxylic acids ( R₂COO-H ) react to make an ester ( R₂COOR₁ ) and water ( HOH ).
The list below correctly orders the types of energy consumed (from largest consumption to smallest) in the U.S.

Petroleum > Natural Gas > Coal > Nuclear Fission > Biomass
Alternative-Fuel vehicles include those that use compressed natural gas, electricity, and hydrogen for fuels. A disadvantage to using these fuels for automobiles as that the technology to use these fuels does not exist.

Multiple Choice (Choose the best answer.)

Use the table at right to answer questions 1 - 4.

Which region possesses the least amount of oil?
Western Europe

Asia

South America

Africa
Which region holds the second largest reserves of petroleum?
N. America

S. America

Africa

Asia
Given the size of its population, what region could impact oil consumption the most if its energy usage increases?
N. America

W. Europe

Africa

Asia
Which region consumes more petroleum relative to its population than North America?
Western Europe

Asia

Middle East

No other region consumes more petroleum relative to its population than does N. America.

Use the graph at right to answer questions 5 - 7.
How many substances were in the mixture that was distilled?
1

2

3

4
Which substance had the highest intermolecular forces?
Substance A

Substance B

Substance C

Substance D
What are the boiling points of the substances being distilled?
30 and 53 ^oC

53 and 80 ^oC

30 and 80 ^oC

It is impossible to tell

Which correctly matches molecular size with boiling point?

Size	Boiling Pt.(^oC)
1 - 4 Carbons	200 - 300
5 - 12 Carbons	40 - 200
12 - 16 Carbons	Less than 40

Size

Boiling Pt.(^oC)

1 - 4 Carbons

40 - 20

5 - 12 Carbons

200 - 3000

12 - 16 Carbons

Less than 40

Size

Boiling Pt.(^oC)

1 - 4 Carbons

Less than 40

5 - 12 Carbons

40 - 200

12 - 16 Carbons

200 - 300

Size

Boiling Pt.(^oC)

1 - 4 Carbons

200 - 300

5 - 12 Carbons

Less than 40

12 - 16 Carbons

40 - 200

Which of the following shows the correct electron dot picture of Nitrogen?
Which of the following shows the corrrect electron dot picture of methane (CH₄)?
Given the conversion factors and , which answer below indicates how many weeks you could you drive on 10 gallons of gasoline?
X X

X X

X X

X X
Automobiles are typically about 25 % efficient. Rank the following uses of energy in a car in terms of greatest to least energy usage.
Motion of the Car > Cylinder Cooling > Exhaust

Exhaust > Motion of the Car > Cylinder Cooling

Cylinder Cooling > Exhaust > Motion of the Car

Exhaust > Cylinder Cooling > Motion of the Car
Which reaction shows a balanced combustion reaction for the burning of methane (CH₄)?
CH₄ C + 2 H₂

CH₄ + 2 O₂ 2 CO₂ + 2 H₂O

CH₄ + O₂ CO + 2 H₂O

CH₄ + O₂ CO₂ + H₂O

An experiment similar to the Burning Candle Lab was performed. The data collected is given at right. Use the data to answer questions 14 - 17 below.
What is the T of the reaction?
^{15.0 o} C

^{35.0 o} C

^{20.0 o} C

^{50.0 o} C
What is the energy given off by the burning candle in Joules?
20.0 J

1500 J

6300 J

6980 J
What is the mass of candle burned?
83.4 g

83.1 g

75.0 g

0.3 g
What is the heat given off per gram of candle burned?
21,000 J / g

5000 J / g

1890 J / g

84 J / g
Isooctane is rated "100" on the octane rating scale. Straight-chain heptane is rated "0" on the octane rating scale. If a type of gasoline gives off the same amount of energy as a mixture of 93% isooctane and 7% heptane, the octane rating of the fuel would be:
Octane 86

Octane 100

Octane 93

Octane 50
"Cracking" refers to . . .
changing large hydrocarbons into smaller ones.

changing small hydrocarbons into larger ones.

changing straight chain hydrocarbons into branched ones.

adding oxygen atoms to hydrocarbons.
Methyl tertiary-butyl ether, MTBE, . . .
boosts octane in fuels.

reduces pollution.

has contaminated ground water.

all of the above are true.
Hydrocarbons can be used to build plastics. In plastics small molecules are joined to make larger ones. One such molecule is ethylene, CH₂=CH₂. Which molecule below shows a dimer of ethylene?
-CH₂-CH₂-CH₂-

-CH₂-CH₂-CH₂-CH₂-

-CH₂-CH₂-CH₂-CH₂-CH₂-

-CH₂-CH₂-CH₂-CH₂-CH₂-CH₂-
Which polymer shown below would be the most flexible?

A. B.

C.
D.
Which polymer shown in problem 24 is both branched and cross-linked?
How many different isomers are there for the molecule C₄H₈?
One

Two

Three

Four
What type of molecule contains this kind of structure?
An Alcohol

An Aromatic

A Carboxylic Acid

An Ester
Which type of molecule contains this kind of structure?
An Alcohol

An Aromatic

A Carboxylic Acid

An Ester
The reactants in a concensation reaction are ____ and ____ . The products are ____ and ____.
Alcohol and Ester . . . Water and Carboxylic Acid

Alcohol and Water . . . Ester and Carboxylic Acid

Carboxylic Acid and Ester . . . Alcohol and Water

Carboxylic Acid and Alcohol . . . Ester and Water
Esters are readily identifiable from their _____.
Acidity

Sweet Smell

Flammability

Toxicity
Which type of energy was the primary fuel until the late 1800s?
Natural Gas

Hydropower

Coal

Biomass
What are is an advantage of an electric car?
a low initial expense

do not require a petroleum-based fuel

batteries have extremely long lives

All of the above are advantages.