Deck 12: Energy and Hydrocarbons

Question 1

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

Answer 1

unsaturated

Question 2

All combustion reactions of fossil fuels

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

Answer 2

give off energy

Question 3

Hydrocarbons with triple bonds are called

A) alkanes
B) alkenes
C) alkynes
D) aromatic hydrocarbons

Answer 3

alkynes

Question 4

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

Question 5

The symbol represents

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

Question 6

The name of the C₂H₅- group is

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

Question 7

Which hydrocarbon is the principal component of natural gas?

A) methane
B) benzene
C) ethylene
D) isooctane

Question 8

Which of the following is ethylene?

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

Question 9

Fermentation of carbohydrates is a source of

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

Question 10

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 11

Which fossil fuel furnishes the most heat energy per gram?

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

Question 12

Which is a characteristic of alkanes?

A) contain C=C
B) general formula C_nH_2n
C) saturated
D) some isomers are cis and trans

Question 13

The complete combustion of C₂H₆ yields

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

Question 14

Which of the following is an isomer of

A)

B)

C)

D)

Question 15

Which is a representation of cyclohexane?

A)

B) C₆H₆
C)

D)

Question 16

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

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

Question 17

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 18

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 19

What is the bond angle around a triple bond?

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

Question 20

A compound containing seven carbon atoms is

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

Question 21

Gasohol contains

A) up to 10% ethanol mixed with unleaded gasoline
B) up to 10% methanol mixed with unleaded gasoline
C) three grams of tetraethyl lead
D) three grams of tertiary-butyl alcohol per gallon

Question 22

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 23

Which is a characteristic of alkanes?

A) contain carbon carbon triple bonds C:::C
B) general formula C_nH_2n-2
C) have only single bonds
D) have isomers are cis and trans

Question 24

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 25

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 26

Which fossil fuel has a molecular structure containing cyclic hydrocarbons?

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

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 aboe 85 $\degree$ C
D) a fuel tha is 85% gasoline and 15% ethanol

Question 28

Which alcohol is called wood alcohol?

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

Question 29

Which fossil fuel burns cleaner and more completely?

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

Question 30

Carcinogens are compounds that are

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

Question 31

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 32

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 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

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 35

Which substance is grain alcohol?

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

Question 36

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

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

Question 37

Gasoline is a

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

Question 38

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 39

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 40

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 41

Identify the alkene?

A) C₅H₁₂
B) C₁₀H₂₀
C) C₃H₄
D) C₁₈H₄₀

Question 42

Identify the alkane?

A) C₅H₁₂
B) C₁₀H₂₀
C) C₃H₄
D) C₁₈H₄₀

Question 43

Which fuel has the largest heat of combustion per gram?

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

Question 44

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

A) C₅H₁₂
B) C₁₀H₂₂
C) C₃H₈
D) C₁₈H₃₆

Question 45

Identify the strongest bond?

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

Question 46

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