Topic 10 Organic chem

Question 1

Catenation

Answer 1

Connected in a chain or series (Eg: carbon forming long chains of covalent bonds)

Question 2

Homologous series

Answer 2

a family of hydrocarbons with similar chemical properties who share the same general formula (eg: alkanes, alkenes)

Question 3

First 4 members of the alkane homologous series

Answer 3

Methan, ethane, propane, butane

Question 4

General formula for alkane–use it to state the molecular formula of hexane

Answer 4

C(n)H(2n+2)

C6H14

Question 5

Functional group

Answer 5

A functional group is responsible for the characteristic property or behavior of a class of compounds. For example, hydroxyl ( –OH) group in alcohols.

Question 6

what are the 13 main class names and their functional group names and suffixes

Answer 6

Alkane–N/A (-ane)
Alkene–alkenyl (-ene)
Alkyne–alkynyl (-yne)
Alcohol–hydroxyl (-anol)
Ether–ether (-oxyalkane)
Aldehyde–carbonyl (-anal)
Ketone–carbonyl (-anone)
Carboxylic acid–carboxyl (-anoic acid)
ester–ester (-anoate)
amide–carboxyamide (-anamide)
amine–amine (-anamine)
nitrile–nitrile (-anenitrile)
arene–phenyl (-benzene)

Question 7

Common features of homologous series

Answer 7

1) same general formula
2) Same functional group
3) a gradual trend in their physical properties (eg:boiling points, density, viscosity) with the rise of molecular mass
4) differ by a -CH2- group
5) similar chemical properties (though the first may differ)

Question 8

The relationship between molecular mass with melting and boiling points + intermolecular strength in a homologous series
Use this to explain the physical states of alkanes

Answer 8

• As the molar mass increases, the strength of the intermolecular forces between the molecules also increases, which results in a higher melting and boiling point.
• The first 4 members of the alkane series are gases, then it becomes liquids then waxy solids.

Question 9

Draw the functional group structure of alkenes

Hence, draw ethene

Question 10

Draw the functional group structure of alkynes

Hence, draw ethyne

Question 11

Draw the functional group structure of alcohol

Hence, draw ethanol

Question 12

Draw the functional group structure of ether

Hence, draw methoxyethane (no. of carb + ether + alkane)

Question 13

Draw the functional group structure of aldehyde

Hence, draw propanal

Question 14

Draw the functional group structure of ketone

Hence, draw propanone

Question 15

Draw the functional group structure of amide

Hence, draw propanamide

Question 16

Draw the functional group structure of amine

Hence, draw ethanamine

Question 17

Draw the functional group structure of nitrile

Hence, draw propanenitrile

Question 18

Draw the functional group structure of arene

Hence, draw ethyl benzene

Question 19

Draw the functional group structure of carboxylic acid

Hence, draw propanoic acid

Question 20

Draw bromomethane

Question 21

Draw methyl methanoate

Question 22

General formula of alkene

Answer 22

C(n)H(2n)

Question 23

General formula of alkyne

Answer 23

C(n)H(2n-2)

Question 24

General formula of alcohol

Answer 24

C(n)H(2n+1)OH

Question 25

General formula of ether

Answer 25

R–O–R' (carbon chains on either sides)

Question 26

General formula of aldehyde

Answer 26

R–CHO

Question 27

General formula of Ketone

Answer 27

R–CO–R'

Question 28

General formula of carbolyxic acid

Answer 28

C(n)H(2n+1)COOH

Question 29

General formula of ester

Answer 29

R–COO–R'

Question 30

List first 6 prefixes of carbon chains

Answer 30

Meth, eth, prop, but, pent, hex

Question 31

Which is the correct order when the following alkanes are placed in order of decreasing boiling point? 1) C4H10 > C3H8 > C2H6 > CH4 2) CH4 > C2H6 > C3H8 > C4H10 3) C4H10 > C2H6 > CH4 > C3H8 4) C4H10 > CH4 > C2H6 > C3H8

Answer 31

1

Question 32

Empirical formula

Answer 32

The simplest whole number ratio of atoms in a compound (eg: CH3)

Question 33

Molecular formula

Answer 33

The actual number of each type of atom in a compound (Eg: C2H6)

Question 34

Full structural formula

Answer 34

all atoms and the bonds between the atoms are shown (Drawn diagram)

Question 35

Condensed structural formula

Answer 35

The same as full structural formulae but the bonds are committed (Eg: CH3CH2CH2CH3)

Question 36

Skeletal formula

Answer 36

using lines, all atoms are omitted leaving only the backbone of the molecule. Single bonds are represented by one line and double bonds are represented by two lines (eg: the skeletal formula of propan-1-ol (CH3CH2CH2OH) omits the carbon and hydrogen atoms)

Question 37

stereochemical formula

Answer 37

shows the relative three-dimensional positions of atoms or groups around a selected carbon atom - a bond sticking out from the plane of the page (towards the viewer) is shown as a solid wedge, whereas a bond directed behind the page (away from the viewer) is shown as a broken line

Question 38

Naming rules

Answer 38

1) Identify the longest straight chain of carbon atoms (eg: meth, prop) 2) Identify the functional group (eg: alkyl, alkenyl, ether) 3) Identify the side chain or substitudent (eg: mthyl, ethyl)

Question 39

Structural isomers–give an example

Answer 39

Compounds with the same molecular formula but different arrangements of atoms (different structural formulae) - eg: pentane and 2-methylbutane

Question 40

position isomerism

Answer 40

when the functional group is attached in different positions

Question 41

Draw But-1-ene and But-2-ene

Question 42

Draw propene