Unit 2-4, Hydrocarbons

Question 1

Organic Chemistry

Answer 1

Major branch of chemistry that deals with compounds of carbon, excluding oxides, and ionic compounds or carbon based ions: carbonate, cyanide, carbide ions

Question 2

Primary sources of hydrocarbons

Answer 2

Coal, oil sands, heavy oil, crude oil, natural gas

Question 3

Raw natural gas

Answer 3

Contains very toxic hydrogen sulfide gas, which forms acidic solutions when mixed with water. Presents a major safety problem for gas-field workers

Question 4

Natural Gas refining

Answer 4

Piped from well site to a treatment plant where water and liquid hydrocarbons are removed from the gas, reacts with amine to remove hydrogen sulfide and carbon dioxide, then converted to elemental sulfur and oxygen

Question 5

Fractional distillation plants

Answer 5

Natural gas is cooled under high pressure to condense all components except methane gas, condensed portion is then distilled to separate out ethane, propane, butane and pentane

Question 6

Alkanes

Answer 6

Hydrocarbons whose empirically determined molecular formulas indicate carbon to carbon bonds are only single bonds (CnH2n+2)

Question 7

Homologous series

Answer 7

Sequence of molecules with similar structure and differing only the number of repeating units (CH2)

Question 8

Saturated Hydrocarbons

Answer 8

Compounds of carbon and hydrogen containing only carbon to carbon single bonds with maximum number of hydrogen atoms bound to each carbon

Question 9

Structural isomers

Answer 9

Compounds with same molecular formula but different structures

Question 10

Branch

Answer 10

Any group of atoms that Is not part of the main structure of the molecule

Question 11

Alkyl branch

Answer 11

Branch consisting of only single bonded carbon and hydrogen atoms

Question 12

Parent chain

Answer 12

Longest continuous chain of carbon atoms (must contain the multiple bond)
Want lowest possible numbers

Question 13

Number of carbon atoms and stem name

Answer 13

1=meth
2=eth
3=prop
4=but
5=pent
6=hex
7=hept
8=oct
9=non
10=dec

Question 14

General form for naming alkanes

Answer 14

(Number of location)- (branch name)(parent chain)

Question 15

Cycloalkanes

Answer 15

When all the carbon to carbon bonds in a cyclic hydrocarbon are single bonds (CnH2n)

Question 16

Unsaturated

Answer 16

Organic compounds with carbon-carbon double or triple bonds, because they have fewer hydrogen atoms (can react with small diatomic molecules)

Question 17

Hydrogenation

Answer 17

Addition of sufficient quantity of hydrogen, converts unsaturated hydrocarbons to saturated ones

Unsaturated + hydrogen»> saturated

Question 18

Alkene

Answer 18

Hydrocarbons with carbon to carbon double bonds, general formula CnH2n

Question 19

Alkyne

Answer 19

Family has chemical properties that can be explained by the presence of a triple bond between carbon atoms. CnH2n-2

Question 20

Cycloalkenes

Answer 20

Molecules have a cycle of carbon atoms with at least one double bond

Question 21

Cracking

Answer 21

An industrial process in which larger hydrocarbon molecules are broken down at high temperatures with or without catalysts to produce smaller hydrocarbon molecules

Question 22

Aliphatic hydrocarbons

Answer 22

Broad class of hydrocarbons including straight or branched chains or rings, of alkanes, alkenes, and alkynes but not aromatics

Question 23

Aromatics

Answer 23

Benzene, and all other carbon compounds that contain benzene- like structures and properties (naturally found in petroleum and are burned)

Question 24

Benzene

Answer 24

C6H6, molecules are non polar, no empirical support that there are double or triple bonds, each carbon is bonded to one hydrogen

Question 25

Phenyl group

Answer 25

The benzene ring (C6H5)

Question 26

Naming aromatic hydrocarbons

Answer 26

If an alkyl branch is attached to a benzene ring, compound is named as (alkyl)benzene If benzene ring is considered the branch of a large molecule, ring is called phenyl branch

Question 27

Fractionation

Answer 27

Technological process in which components of crude oil are physically separated by means of their differences in boiling points, to get from one level to the next vapours have to force their way through the liquid in the next tray

Question 28

Fractions

Answer 28

Product in the fractionation process, identified by its boiling point range or by the approximate number of carbon atoms in component molecules Fractions with lowest boiling points = smallest molecules= fewer electrons= weaker London forces

Question 29

Solvent Extraction

Answer 29

Solvent is added to selectively dissolve and remove an impurity or to separate some useful products from a mixture

Question 30

Dewaxing

Answer 30

Simple process of cooking a mixture to precipitate the larger wax fraction

Question 31

Thermal cracking

Answer 31

Cracking that is accomplished using only High temperatures and pressures (wasteful)

Question 32

Hydrocracking

Answer 32

Combination of catalytic cracking and hydrogenation, is used for heavier feedstock and those containing complex aromatic compounds

Question 33

Catalytic cracking

Answer 33

Breaks apart larger molecules, presence of catalyst along with less severe reaction conditions, produces more desirable fractions and less residual materials

Question 34

Catalytic reforming

Answer 34

Chemical process involved in converting molecules in gasoline fraction into aromatic gasoline molecules, have better burning properties. Hydrogen (by product) is recycled in other processes

Question 35

Alkylation

Answer 35

Improves quality of gasoline by increasing branching of molecules, also called isomerization, converts molecule into a branched isomer

Question 36

Sulfur in gasoline

Answer 36

Pollution problem, gasoline in burned and sulfur emissions reduce air quality, decrease pH of rain= acid deposition Comes from cars, reduces effectiveness of catalytic converter and increases the quantity of other pollutants

Question 37

Reduce sulfur content

Answer 37

Hydrogenation or hydrotreating>> hydrogen gas reacts with sulfur atoms in gasoline molecules to produce hydrogen sulfide gas which is converted to sulfur and water in Claus converter

Question 38

Complete combustion

Answer 38

(Exothermic) a hydrogen (fuel) reacts with oxygen to produce carbon dioxide and water vapour as the only chemical products Hydrocarbon+O2>>>> CO2 + H2O

Question 39

Incomplete Combustion

Answer 39

Include reactions that produce carbon monoxide and soot or any combination of carbon dioxide, carbon monoxide, and carbon in addition to water and energy Hydrocarbon + O2>>> xC(s) + yCO(g) + H2O(g)

Question 40

Oxygenators

Answer 40

Alcohol, provide additional oxygen to Combustion reaction and make the combustions more complete, shown by reduced quantity of CO and soot

Question 41

Bonding capacity

Answer 41

Hydrogen: 1 Carbon: 4 Oxygen: 2 Nitrogen: 3

Question 42

Functional groups

Answer 42

Characteristic arrangements of atoms that are responsible for compound family properties

Question 43

Chemical reactions representative of alkanes

Answer 43

Combustion, cracking, reformation

Question 44

Chemical reactions representative of alkenes

Answer 44

Combustion, hydrogenation

Question 45

Chemical reactions representative of alkynes

Answer 45

Combustion, hydrogenation (double)

Question 46

Chemical reactions representative of Aromatics

Answer 46

Combustion