4.7 organic chemistry

Question 1

what is crude oil and what is it made from

Answer 1

finite resource found in rocks. Crude oil is the remains of an ancient biomass consisting of plankton that was buried in mud

Question 2

what is crude oil a mixture of

Answer 2

a number of compounds. Most compounds are hydrocarbons, which are molecules made up from only hydrogen and carbon atoms.

Question 3

what are most hydrocarbons in crude oil called

Answer 3

alkanes, which only contain single covalent bonds making them saturated hydrocarbons

Question 4

general formular for the homologous series of alkanes

Answer 4

Cn H2n+2

Question 5

formula of methane

Answer 5

CH4

Question 6

formula of ethane

Answer 6

C2H6

Question 7

formula of propane

Answer 7

C3H8

Question 8

formula of butane

Answer 8

C4H10

Question 9

products of hydrocarbon through combustion

Answer 9

complete combustion: Carbon dioxide and Water.

Question 10

A larger hydrocarbon molecule/chain means what?

Answer 10

lower flammability and volatility (how easily a liquid vaporises), higher viscosity and higher boiling points

Question 11

why do larger hydrocarbon molecules / chains have higher boiling points

Answer 11

because the molecules are larger, the intermolecular forces are stronger/large, so more energy is required to break them

Question 12

products of incomplete combustion

Answer 12

carbon monixide, carbon particles known as soot

Question 13

describe the processes in fractional distillation

Answer 13

crude oil is heated outside of column where most of it vapourises, mixture of vapour and liquids are passed into the bottom of the fractionating tower. Inside the tower is a concentration gradient, meaning that the top of the tower is cooler and the bottom is hotter. vapour rises up the column and cools and then condenses. each fraction has a different boiling point and condenses at different levels Larger/longer hydrocarbons condense towards the bottom as there are more intermolecular forces which require more energy to break. smaller hydrocarbons condense towards the top.

Question 14

uses of LPG

Answer 14

cooking equipment, heating appliances

Question 15

uses of petrol

Answer 15

fuel for cars, heating appliances, produces electricity

Question 16

uses of kerosene

Answer 16

fuel for jet

Question 17

uses of diesel oil

Answer 17

fuel for cars, trains, large vehicles

Question 18

uses of heavy fuel oil

Answer 18

fuel for large ship engines / marine boats, power stations

Question 19

uses of bitumen

Answer 19

used to make tarmac in road making

Question 20

what is the cracking of hydrocarbons

Answer 20

when larger hydrocarbons are broken down to produce smaller and more useful molecules

Question 21

describe the cracking process

Answer 21

heating the hydrocarbons to vapourise them, the vapours are either passed over a hot catalyst or mixed with steam and heated to a very high temperature

Question 22

uses of cracking products

Answer 22

high demand for fuels with small molecules, like petrol and diesel
alkanes are used to produce polymers and as starting materials for the production of many other chemicals

Question 23

what type of reaction is cracking

Answer 23

thermal decomposition reactions

Question 24

products of cracking

Answer 24

alkanes and unsaturated hydrocarbons called alkenes

Question 25

alkenes are hydrocarbons with what?

Answer 25

a double carbon - carbon bond. they are unsaturated as they have more than one double carbon-carbon covalent bond. they have 2 fewer hydrogen atoms than the alkane with same number of carbon atoms

Question 26

alkenes are more what than alkanes

Answer 26

alkenes are more reactive.

Question 27

alkene reaction with bromine water

Answer 27

turning it from orange to colourless

Question 28

general formular for homologous series in alkenes

Answer 28

CnH2n

Question 29

draw the first four members of the homolgous series of alkenes

Answer 29

ethene, proprene, butene and pentene DRAW IT ON PAPER MAKE SURE ITS CORRECT

Question 30

formula of ethene

Answer 30

C2H4

Question 31

formula of propene

Answer 31

C3H6

Question 32

formula for butene

Answer 32

C4H8

Question 33

formula for pentene

Answer 33

C5H10

Question 34

functional group of alcohols

Answer 34

OH

Question 35

give names of alcohols

Answer 35

methanol, ethanol, propanol, butanol

Question 36

what do alcohols do to react

Answer 36

dissolve in water to form a neutral solution react with sodium to produce hydrogen burn in the air

Question 37

how do alcohols turn into carboxylic acids

Answer 37

they can be oxidised by oxidising agents

Question 38

ethanol + oxygen -> ?

Answer 38

ethanoic acid

Question 39

uses of alcohols

Answer 39

used as fuels, solvents, alcohol in alcoholic drinks

Question 40

what is fermentation

Answer 40

when aqueous solutions of ethanol are produced when sugar solutions are fermented using yeast

Question 41

complete the equation glucose -> ?

Answer 41

ethanol + carbon dioxide

Question 42

conditions needed for fermentation

Answer 42

yest, no air, temperatures from 30-40 degrees C

Question 43

optimum temperature for fermentation and why?

Answer 43

38 degrees C lower temperatures cause the reaction to be too slow higher temperatures causes the yeast to die and enzymes to denature

Question 44

fermentation is done in the absence of what?

Answer 44

air / oxygen presence of air can cause extra reactions to occur, if the ethanol oxidises, it can produce ethanoic acid (vinegar)

Question 45

functional group of carboxylic acids

Answer 45

COOH

Question 46

carboxylix acids do what to react

Answer 46

dissolve in water to produce acidic solutions react with carbonates to produce carbon dioxide reacts with alcohols in the presence of an acid catalyst to produce esters

Question 47

what kind of acids are carboxylic acids

Answer 47

weak acids as they do not ionise completely when dissolved in water.

Question 48

what are esters

Answer 48

made from the reaction of carboxylic acids and alcohols in the presence of an acid catalyst eg. sulfuric acid

Question 49

functional group of esters

Answer 49

-COO-

Question 50

whats the ester produced from ethanol and ethanoic acid

Answer 50

ethyl ethanoate

Question 51

what is addition polymerisation

Answer 51

Addition polymerisation is a process involving many small, unsaturated monomers combining to form one large polymer molecule

Question 52

what happens during additional polymerisation to alkenes

Answer 52

the double bonds open up and many small unsaturated molecules join together to form very large saturated molecules.

Question 53

what is condensation polymerisation

Answer 53

involves monomers with two functional groups. when these monomers react they join together, usually using small molecules such as water

Question 53

products of condensation polymerisation

Answer 53

water

Question 54

amino acids have what functional groups in a molecule

Answer 54

amino acids have two functional groups in a molecule

Question 55

amino acids react by what

Answer 55

condensation polymerisation produce polypeptides

Question 56

when different amino acids are combined, what is produced?

Answer 56

proteins