C7 Organic Chemistry

Question 1

Organic Chemistry

Answer 1

The study of compounds containing carbon.

Question 2

Hydrocarbon

Answer 2

A compound containing only hydrogen and carbon.

Question 3

Saturated

Answer 3

Contains only single bonds, bromine water stays yellow-orange.

Question 4

Unsaturated

Answer 4

Contains one or more double bonds, bromine water goes colourless.

Question 5

Functional Group

Answer 5

Atom/group of atoms responsible for most of the chemical reactions of a compound.

Question 6

Homologous Series

Answer 6

Series of hydrocarbon compounds with the same functional group and similar chemical properties.

Question 7

Polymer

Answer 7

Long-chain molecules made from joining together monomers.

Question 8

Addition Reaction

Answer 8

Alkene polymerisation

Question 9

Condensation Reaction

Answer 9

Dicarboxylic + diol
Dicarboxylic + diamine
Amino acid

Forms polymer and water

Question 10

LHCRH for Small Alkanes

Answer 10

Low BPT
High Flammability
Clean Flame
Runny Viscosity
High Volatility

Question 11

Uses of Alkanes

Answer 11

Fuel
Cracking

Question 12

Fractional Distillation

Answer 12

Vaporised oil is transferred to a column which is hot at the bottom and cool at the top. Gases cool as they rise up and eventually are cool enough to liquify. Alkanes liquify at different heights due to their different bpts, thus bigger alkanes are at the bottom and smaller alkanes are at the top.

Question 13

Value of Alkenes

Answer 13

Makes polymers, tends to undergo incomplete combustion

Question 14

Hydrogenation

Answer 14

150ºC with nickel catalyst; makes alkanes

Question 15

Hydration

Answer 15

High temperature with conc. H3PO4 catalyst; makes alcohols

Question 16

Cracking

Answer 16

Thermal decomposition of long alkanes into more valuable products.

Question 17

Methods of Cracking

Answer 17

Catalytic (vaporise and pass over hot catalyst)
Steam (mix with steam at high temperatures)

Question 18

Reason for Cracking

Answer 18

Surplus of long alkanes converted into high-demand shorter alkanes and alkenes.

Question 19

Uses of Alcohols

Answer 19

Good fuels (biofuels)
Solvents (perfumes)
Alcoholic drinks

Question 20

Fermentation Conditions

Answer 20

Presence of carbohydrate
Mixture is warm ~30ºC
No air (otherwise oxidised into carboxylic acid)
Aqueous
Yeast added

Question 21

Fermentation

Answer 21

glucose -> ethanol + carbon dioxide

requires fractional distillation

Question 22

Biofuel Advantages

Answer 22

Carbon neutral
Renewable

Question 23

Alcohol Reactions

Answer 23

Alcohol + water -> neutral pH (green in universal indicator)
Burns with clean flame
Potassium dichromate goes from orange to green as the alcohol is oxidised
Fizzes when sodium is added, hydrogen produced

Question 24

Carboxylic Acid

Answer 24

-COOH

Question 25

Carboxylic Acid Reactions

Answer 25

Add to water and test pH -> orange Add sodium hydrogencarbonate -> fizzes gently Add alcohol and conc. H2SO4 catalyst -> ester

Question 26

Uses of Esters

Answer 26

Perfumes, printing ink, flavourings

Question 27

Polymerisation Features

Answer 27

Carboxylic acid loses -OH Alcohol loses -H Amine loses -H

Question 28

Biochemistry

Answer 28

Proteins are polymers of amino acids Starch & cellulose are polymers of glucose DNA are polymers of nucleotides

Question 29

Strong vs Weak Acids

Answer 29

Strong: All molecules break down into H+ ions when added to water Weak: Only a fraction of molecules break down into H+ ions when added to water