Organic Chemistry

Question 1

Homologous series

Answer 1

Compounds that have a similar chemical structure and chemical properties

Question 2

Organic compounds

Answer 2

Compounds consisting of carbon atoms most commonly covalently bonded to hydrogen, nitrogen, phosphorus or oxygen atoms

Question 3

Functional group

Answer 3

Specific groups of atoms within a compound that affect the properties of the compound.

Question 4

Alkanes

Answer 4

Saturated molecules - all carbons to carbon single bonds

Question 5

Alkenes

Answer 5

Unsaturated molecules - contains at least one carbon-to-carbon double bond

Question 6

Alkane General Formula

Answer 6

CnH2n+2

Question 7

Alkene General Formula

Answer 7

CnH2n

Question 8

Haloalkane General Formula

Answer 8

CnH2n+1 X

Question 9

Isomers

Answer 9

Molecules that have the same molecular formula but a different structural formula.

Question 10

Fractional Distillation

Answer 10

Fractional distillation separates a mixture into a number of different parts, calledfractions.

A tall fractionating column is fitted above the mixture.
The column is hot at the bottom and cool at the top.

Question 11

Why do the longer hydrocarbon chains take more heat energy to change state from solid to liquid or liquid to gas?

Answer 11

The longer the chain, the stronger the dispersion forces there are between the molecules thus requiring more energy to break.

Question 12

Viscosity

Answer 12

Viscosityis a measure of a fluid’s resistance to flow.

Question 13

When the hydrocarbon goes through a state change of liquid to gas, which bonds are broke?

Answer 13

Weak intermolecular forces (dispersion) are broken when the hydrocarbon reaches its boiling point and transitions from liquid to a gas. The covalent bonds between the atoms do not beak. This would required a higher amount of energy.

Question 14

Difference in boiling point of small and larger hydrocarbons

Answer 14

Smaller the molecule the lower the boiling point because there are lesson intermolecular forces between the molecules.

And therefore, less energy required to break them.

Question 15

Cracking

Answer 15

Large hydrocarbon molecules can be broken down into smaller molecules using a catalyst.

Question 16

Cracking Method

Answer 16

The hydrocarbon molecules are heated until they turn into vapour, and then mixed with a catalyst.

Question 17

Combustion (complete and incomplete)

Answer 17

Complete combustion hydrocarbon is burned in excess oxygen
hydrocarbon + oxygen → carbon dioxide + water
Incomplete combustion hydrocarbon is burned in limited oxygen
hydrocarbon + oxygen → carbon monoxide + water or
hydrocarbon + oxygen → carbon + water

Question 18

Substitution reaction (with drawn example)

Answer 18

Oneatomis swapped with another atom.
Alkanesundergo asubstitution reactionwithhalogensin the presence of light.

Question 19

Addition reaction (with halides, including conditions)

Answer 19

Double bond breaks and addition atoms are added.

Question 20

Bromine water test (including equation, including conditions)

Answer 20

(type of addition reaction). A test to determine whether a solution contains alkanes or alkenes.
There is no change when bromine water is mixed with an alkane.
The bromine water goes from orange to colourless when it is mixed with an alkene.

Question 21

Hydrogenation (addition reaction with H2, including conditions)

Answer 21

Alkene + hydrogen (150degreesC and Ni catalyst)→ alkane

Question 22

Hydration (addition reaction with H2O, including conditions)

Answer 22

Alkene + water (steam) (catalyst + 300degrees C) → alcohol

Question 23

Ethanol production (including advantages and disadvantages) Fermentation of glucose

Answer 23

Fermentation of glucose:
C6H12O6 (yeast catalyst) → C2H5OH + CO2
Advantages: Simple method and Uses renewable resources
Disadvantages: Not a continuous process, slow reaction and produces low purity ethanol

Question 24

Ethanol production (including advantages and disadvantages) Hydration

Answer 24

Ethene + steam
C2H4 + H2O (g) → C2H5OH
Advantages: Small-scale equipment, continuous process, reaction is fast and produces high purity ethanol
Disadvantages: Uses non-renewable resources

Question 25

Alcohol Homologous Series

Answer 25

Organic compounds containing a hydroxyl (-OH) group are called alcohols

Question 26

Carboxylic acid name ends in …

Answer 26

Name ends in -oic acid

Question 27

Alkyl Halides

Answer 27

Organic compounds containing halogens are called alkyl halides (group 7 elements)

Question 28

Polymerisation

Answer 28

The formation of a large molecule (polymer) from many monomer subunits.

Question 29

Monomers

Answer 29

Monomer: small molecules that can join to form a polymer

Question 30

Polymers

Answer 30

Polymer: large molecules built up from small units (monomers)