Deck 12: Energy and Hydrocarbons

Question 1

A compound containing seven carbon atoms could be

A) heptane.
B) octane.
C) hexane.
D) nonane.

Answer 1

heptane.

Question 2

The name of the C₂H₅- group is

A) methyl
B) ethyl.
C) propyl.
D) butyl.

Answer 2

ethyl.

Question 3

Which of the following will not improve the octane rating of a gasoline?

A) increasing the percentage of branched-chain hydrocarbons
B) increasing the percentage of aromatic hydrocarbons
C) increasing the percentage of straight-chain hydrocarbons
D) adding octane enhancers

Answer 3

increasing the percentage of straight-chain hydrocarbons

Question 4

Which process is used to increase the amount of the gasoline fraction in refining to match commercial demand?

A) reforming
B) oxygenating
C) cracking
D) gasification

Question 5

Fermentation of carbohydrates is a source of

A) MTBE.
B) ethanol.
C) ethers.
D) methanol.

Question 6

The hydrocarbon represented by the following model would be called

A) unsaturated.
B) aromatic.
C) an alkene.
D) all of the above

Question 7

Which is a characteristic feature of alkenes?

A) general formula of C_nH_{2n + 2}
B) tetrahedral geometry
C) unsaturated
D) hydrocarbons which contain only single bonds

Question 8

The symbol shown below.represents

A) a cycloalkane.
B) cyclohexane.
C) hexane.
D) benzene.

Question 9

All combustion reactions of fossil fuels

A) give off energy.
B) are complete reactions with oxygen.
C) are endothermic reactions.
D) are l00% efficient.

Question 10

Which is a representation of cyclohexane?

A)
B) C₆H₆
C)
D)

Question 11

Coal gasification is a process for making

A) synthesis gas.
B) molecules that are precursors of organic chemicals.
C) methane.
D) all of these

Question 12

What is the bond angle around a triple bond?

A) 90 ^$\circ$
B) l09.5 ^$\circ$
C) l20 ^$\circ$
D) l80 ^$\circ$

Question 13

Which alcohol is called wood alcohol?

A) ethanol
B) isopropyl alcohol
C) 1-propanol
D) methanol

Question 14

Which of the following is ethylene?

A) CH₂=CHCH₃
B) CH₂=CH₂
C) H-C=C-H
D) CH₃-CH₃

Question 15

The complete combustion of C₂H₆ yields

A) C₂H₄ and H₂.
B) CO and H₂O.
C) CO₂ and H₂O.
D) C and H₂.

Question 16

Butane [CH₃CH₂CH₂CH₃] and 2-methylpropane [(CH₃)₂CHCH₃] are

A) stereoisomers.
B) cis-trans isomers.
C) structural isomers.
D) optical isomers.

Question 17

At current usage rates, world reserves of which fuel below are estimated to last for the least number of years?

A) natural gas
B) hydrogen
C) petroleum
D) coal

Question 18

Which is a characteristic of alkanes?

A) contain C=C
B) general formula C_nH_2n
C) saturated
D) cis-trans isomers

Question 19

Which fossil fuel furnishes the most heat energy per gram?

A) petroleum
B) charcoal
C) natural gas
D) coal

Question 20

Consider the following structure. Which of the following is an isomer of this structure?

A)
B)
C)
D)

Question 21

Which fossil fuel has a molecular structure containing cyclic hydrocarbons?

A) coal
B) liquid propane
C) natural gas
D) none of these

Question 22

What are the bond angles around the carbon atoms in alkanes?

A) 90 ^$\circ$
B) l09.5 ^$\circ$
C) l20 ^$\circ$
D) l80 ^$\circ$

Question 23

What term is used to describe the amount of heat energy released from burning?

A) heat of fusion
B) heat of vaporization
C) heat of combustion
D) heat of formation

Question 24

The octane rating of straight run gasoline from fractional distillation of petroleum can be raised by

A) catalytic reforming.
B) adding tertiary-butyl alcohol.
C) adding ethanol.
D) all of the above

Question 25

Which substance is grain alcohol?

A) methanol
B) ethanol
C) MTBE
D) benzene

Question 26

Petroleum is separated into fractions in the refining process. Which of the following fractions has molecules with the largest size?

A) gas
B) kerosene
C) paraffin wax
D) straight-run gasoline

Question 27

The fuel identified as M85 is

A) a substance with a molar mass of 85.
B) a fuel mixture of 85% methanol and 15% gasoline.
C) a fuel with a boiling point above 85 ^$\circ$ C.
D) a fuel that is 85% gasoline and 15% ethanol.

Question 28

Which fossil fuel burns cleaner and more completely?

A) coal
B) natural gas
C) petroleum
D) wood

Question 29

Gasoline is a

A) single, simple hydrocarbon.
B) single, complex hydrocarbon.
C) mixture of C₁₂-C₁₆ hydrocarbons.
D) mixture of C₅-C₁₂ hydrocarbons.

Question 30

Which of the following is not true about the compound MTBE?

A) it is an ether
B) made by fermentation
C) it is a carcinogen
D) used to oxygenate gasoline

Question 31

Carcinogens are compounds that are

A) never used as fuels.
B) cancer causing agents.
C) not found in petroleum.
D) rarely aromatic.

Question 32

Fractional distillation of petroleum

A) separates and purifies all of the hydrocarbons in crude oil.
B) separates fractions, each of which contain many hydrocarbons.
C) is the final step in refining gasoline.
D) fractions large molecules into smaller ones.

Question 33

The combustible products of most coal gasification techniques are

A) nitrogen, hydrogen, and carbon monoxide.
B) nitrogen and hydrogen.
C) hydrogen and carbon monoxide.
D) carbon dioxide and hydrogen.

Question 34

Gasohol (E85) contains

A) 15% ethanol mixed with unleaded gasoline.
B) 10% methanol mixed with unleaded gasoline.
C) 85% ethanol mixed with unleaded gasoline.
D) three grams of tertiary-butyl alcohol per gallon.

Question 35

Which of the following is not true about benzene?

A) has the formula C₆H₁₂
B) is a carcinogen
C) increases the octane rating of gasoline
D) is a cyclic hydrocarbon

Question 36

Which fuel has the largest heat of combustion per gram?

A) hydrogen
B) ethanol
C) wood
D) gasoline

Question 37

The purpose of coal gasification is to

A) pressurize coal so the coal will be compact.
B) produce a relatively clean burning, gaseous fuel.
C) make more consumer products from coal.
D) put railroads out of business.

Question 38

Octane ratings are based on comparison of the fuel being tested with the knocking properties of mixtures of

A) hexane and heptane.
B) isooctane and hexane.
C) isooctane and heptane.
D) heptane and nonane.

Question 39

Which of the following compounds would you expect to have the highest octane rating?

A) pentane, C₅H₁₂ , CH₃CH₂CH₂CH₂CH₃
B) hexane, C₆H₁₄ , CH₃CH₂CH₂CH₂CH₂CH₃
C) isooctane, C₈H₁₈ , (CH₃) ₃CCH₂CH(CH₃) ₂
D) heptane, C₇H₁₆ , CH₃CH₂CH₂CH₂CH₂CH₂CH₃

Question 40

A coal gasification process involving a catalyst, carbon monoxide, hydrogen, steam and coal produces

A) only CO.
B) liquid petroleum.
C) octane.
D) methane and carbon dioxide.

Question 41

The structure below represents an aromatic hydrocarbon which is unsaturated and has a higher octane rating than hexane.

Question 42

Consider the following model of ethanol, CH₃CH₂OH. During the complete combustion of ethanol with oxygen, carbon dioxide and water are formed.
The number of carbon to hydrogen single bonds that are broken is_______.

Question 43

The following two hydrocarbon models represent structural isomers of each other.

Question 44

Consider the following model of ethanol, CH₃CH₂OH. During the complete combustion of ethanol with oxygen, carbon dioxide and water are formed.
In the balanced equation for the combustion of one mole of ethanol, the coefficient of water is _____.

Question 45

Which of the bond types shown below gives rise to cis-trans isomers?

A) C - C
B) C - H
C)
D) C -C

Question 46

Identify the alkane shown below.

A) C₅H₁₂
B) C₁₀H₂₀
C) C₃H₄
D) C₁₈H₄₀

Question 47

Consider the following model of ethanol, CH₃CH₂OH. During the complete combustion of ethanol with oxygen, carbon dioxide and water are formed.
Using the data in the following table, The amount of energy required to break all the C-H bonds in ethanol is ______kJ.

Question 48

Consider the following model of ethanol, CH₃CH₂OH. During the complete combustion of ethanol with oxygen, carbon dioxide and water are formed.
Using the data in the following table, The amount of energy released in the formation of all the O-H bonds in the product water is ______kJ.

Question 49

Which of the bond types shown below is the strongest?

A) C - C
B) C = O
C) O - H
D) O = O

Question 50

Which hydrocarbon would be isolated at the top of a fractionation column?

A) C₅H₁₂
B) C₁₀H₂₂
C) C₃H₈
D) C₁₈H₃₆

Question 51

The following compound could represent the principle component of natural gas.

Question 52

Identify the alkene shown below.

A) C₅H₁₂
B) C₁₀H₂₀
C) C₃H₄
D) C₁₈H₄₀

Question 53

The hydrocarbon represented by the model below has cis and trans isomers.

Question 54

The correct name of the following compound is 2-dimethylpentane.

Question 55

The hydrocarbon model shown below could represent a saturated compound with the general formula C_nH_2n+2.

Question 56

Among the alkanes, alkenes, and alkynes only the alkanes contain only single bonds.

Question 57

Consider the following model of ethanol, CH₃CH₂OH. During the complete combustion of ethanol with oxygen, carbon dioxide and water are formed.
During the combustion of one mole of ethanol, the number of O-H bonds formed is _____.