Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CHEM Unit 2 Nature’s Chemistry > P1- The Homologous Series > Flashcards

P1- The Homologous Series Flashcards

1
Q

Hydrocarbon

A

Substance containing only hydrogen and carbon
3 families: alkanes, alkenes, cycloalkanes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Alkanes

A

Always end in ane
Prefix indicating number or carbons
Saturated- only single bonds
Flammable so make fuels
Insoluble
Readily undergo combustion reactions in the prescence of oxygen
E.g methane- fuel to make heat and light
propane- home and water heating
octane- proper functioning in modern engines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Drawing hydrocarbons

A

Carbon group 4- valency 4- 4 bonds
Hydrogen- group 1- valency 1- 1 bond
Molecular formula- number of each element
Full structural formula- atoms and all bonds
Shortened structural formula- how hydrogen atoms arranged around carbon without showing bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

First 8 alkanes

A

Number of Molecular Full Shortened
Hydrocarbon Carbons Formula Formula Formula

                                                                                                   H
                                                                                                   |                                                                                           Methane                       1                      CH4                       H - C - H                           CH4
                                                                                                   |
                                                                                                   H

                                                                                                H   H
                                                                                                 |   |            Ethane                          2                      C2H6                   H - C - C - H                    CH3CH3
                                                                                                 |   |
                                                                                                H   H
  
                                                                                             H   H   H
                                                                                             |    |   |    Propane                        3                     C3H8                  H - C - C - C - H              CH3CH2CH3
                                                                                             |    |   |
                                                                                            H    H   H

Butane 4 C4H10 CH3CH2CH2CH3

Pentane 5 C5H12 CH3CH2CH2CH2CH3

Hexane 6 C6H14 CH3CH2CH2CH2CH2CH3

Heptane 7 C7H16 CH3CH2CH2CH2CH2CH2CH3

Octane 8 C8H18 CH3CH2CH2CH2CH2CH2CH2CH3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Homologous series

A

Family of compounds with the same general formula, similar chemical properties and gradually changing physical properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where do alkanes come from

A

From natural gas or from fractional distillation of crude oil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

General formula of alkanes

A

CnH2n+2
2 x number of carbons + 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Melting and boiling points of hydrocarbons

A

Increase because as the molecular size increases, the strength of the intermolecular forces increases so more heat energy is required to separate large molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cycloalkanes

A

Start with cyclo and end in ane
Contain a ring of carbons
Saturated because contain carbon to carbon single bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cycloalkanes general formula

A

CnH2n

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

First 8 members of cycloalkanes

A

Name Number of carbon atoms Molecular formula

Cyclopropane                      3                                           C3H6

Cyclobutane                        4                                           C4H8

Cyclo-pentane                     5                                           C5H10

Cyclohexane                       6                                            C6H12

Cyclo-heptane                    7                                            C7H14

Cyclo-octane 8 C8H16

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Alkenes

A

End in ene
Prefix indicating number of carbon atoms
Contain at least one carbon to carbon double bond making it unsaturated and reactive
Insoluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Alkenes general formula

A

CnH2n

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Alkenes uses

A

Making polymers (plastics)
Industrial production of ethanol
Fuels
Solvents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

First 7 members of the alkenes

A

Name Carbons Molecular Full Short

                                                                                                 H H
                                                                                                 |  | Ethene              2                                C2H4                              C=C                              CH2=CH2
                                                                                                 |  |
                                                                                                 H H 

                                                                                            H    H                          
                                                                                            |     | Propene           3                               C3H6                          C=C-C-H                          CH2=CHCH3
                                                                                            |  |  |
                                                                                            H H  H 

                                                                                          H  H     H
                                                                                          |   |     | Butene             4                              C4H8                          C=C-C-C-H                    CH2=CH2CHCH3
                                                                                          |   | |  |
                                                                                          H  H H H

                                                                                         H H     H H
                                                                                         |  |     |  | Pentene           5                            C5H10                        C=C-C-C-C-H               CH2=CH2CHCH2CH3
                                                                                         |  |  | |  |
                                                                                        H  H H H H

                                                                                      H H    H H H
                                                                                      | |       | | | Hexene            6                           C6H12                       C=C-C-C-C-C-H       CH2=CH2CHCH2CH2CH3
                                                                                      |  |  |  | | | 
                                                                                      H H H H H H
 
                                                                            H H     H H H H
                                                                            |  |      | |  |  | Heptene           7                     C714                     C=C-C-C-C-C-C-H      CH2=CH2CHCH2CH2CH2CH3
                                                                             | |  |  | |  | | 
                                                                            H H H H H H H

                                                                   H H     H H H H H
                                                                    | |      |  | | |  |  Octene            8                    C8H16            C=C-C-C-C-C-C-C-H    CH2=CH2CHCH2CH2CH2CH2CH3
                                                                    | |   | |  |  | | |
                                                                    H H H H H H H H
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Branched chain alkanes

A

Carbon atoms attached to side of main chain
End in yl
Prefix indicating number of carbons

17
Q

First 4 branch names

A

Methyl
Ethyl
Propyl
Butyl

18
Q

Naming branched chain alkanes

A

Count from side closest to branch

Position of branch(es) - prefix for number of branches name of branch name of chain

19
Q

Naming branched chain alkenes

A

Count from side closest to double bond

Position of branch - prefix for no. branches name of branch alkene prefix - double bond position - ene

20
Q

Isomer

A

Molecules with the same molecular formula but different structural formula
They usually have different physical properties

21
Q

Reactions that hydrocarbons take place in

A

Combustion
Addition reactions of alkenes
Cracking

22
Q

Combustion

A

Burning
Forms carbon dioxide and water in a plentiful supply of oxygen
Forms carbon monoxide and water in a limited supply of oxygen

Hydrocarbon + oxygen —> carbon dioxide + water

23
Q

Addition reactions of alkenes

A

Halogenation
Hydrogenation
Hydration

The carbon to carbon double bond breaks and other reactants add across the double bond

24
Q

Halogenation

A

Testing for unsaturation by testing the effect hydrocarbons have on bromine solution
Halogens form dihaloalkanes

Alkene + bromine —> dibromoalkane
Bromine - Br-Br

25
Q

Hydrocarbon effect on bromine solution

A

Alkanes and cycloalkanes are saturated so the bromine solution stays the same because no more atoms can be added to the molecule because each carbon is already bonded to 4 other atoms
Alkenes are unsaturated so bromine water is decoloroised

26
Q

Hydrogenation

A

Hydrogen forms alkanes

Alkene + hydrogen —> alkane
Hydrogen H-H

27
Q

Hydration

A

Water forms alcohols
Alkene + water —> alcohol
Alcohol- H-OH

28
Q

Cracking

A

A process in which long chain hydrocarbon molecules are broken down into shorter, more useful molecules using heat and a catalyst
Catalyst allows reaction to be done at a lower temperature
Delivery tube should be removed before heating is stopped
Produces a mixture of alkanes and alkenes because the long chain hydrocarbon molecule can break at different points
Equation should have same number of carbon and hydrogen atoms on products and reactants sides

29
Q

What is cracking used for

A

To convert the larger, less valuable fractions of crude oil into petrol

CHEM Unit 2 Nature’s Chemistry (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions