organic chemistry

Question 1

what is crude oil and where is it found

Answer 1

a finite resource round in rocks
formed from ancient biomass (mainly plankton)

Question 2

what do most compounds in crude oil consist of

Answer 2

carbon and hydrogen (hydrocarbons) most of which are alkanes

Question 3

how do you separate crude oil into its compounds and why is this possible

Answer 3

fractional distillation
each compound has a different boiling point

Question 4

explain how fractional distillation is used to separate crude oil into its compounds

Answer 4

1. the oil is put into a chamber and is heated until most of it is a liquid
2. this is then passed into a fractionating column where it is hotter at the bottom and gets cooler
3. the hot gasses rise until they reach a region that is cooler than its boiling point where it condenses into a liquid

Question 5

what are short chains of hydrocarbons used for

Answer 5

used to produce fuels such as petrol and diesel

Question 6

what are petrochemicals and what are they used for

Answer 6

the substance’s from crude oil

used as feedstock
- lubricants, polymers, solvents, detergents

Question 7

what are homologous series

Answer 7

a group of similar compounds with similar properties

Question 8

what is the general formular for a hydrocarbon

Answer 8

Cn Hn+2

Question 9

what are the first four hydrocarbons (alkanes) (names)

Answer 9

methane, propane, ethane, butane

Question 10

what are the formulars for the first four hydrocarbons (alkanes)

Answer 10

CH4
C2H6
C3H8
C4H10

Question 11

what is a saturated compound

Answer 11

organic compounds that have only one carbon to carbon single bond no double bonds

Question 12

what are some properties of hydrocarbons. include boiling point, flammability etc

Answer 12

• boiling points increase as alkane gets longer
• the four first hydrocarbons are gasses
• the shorter the hydrocarbon the more volatile it is (likely to evaporate)
• the longer the more viscus
• shorter hydrocarbons are more flammable

Question 13

what is the main use of a hydrocarbon

Answer 13

for fuel

Question 14

how are hydrocarbons used for fuel

Answer 14

complete combustion

Question 15

what is the equation for complete combustion with a hydrocarbon

Answer 15

hydrocarbon + oxygen —- co2 + water

Question 16

what is the balanced equation for complete combustion of propane

Answer 16

C3H8 + 5O2 ——- 3CO2 + 4O2

Question 17

what is the balanced equation for complete combustion of nonane

Answer 17

C9H20 + 14O2 —— 9CO2 + 10O2

Question 18

what is cracking used for

Answer 18

breaking up the longer chains of hydrocarbons into smaller ones

Question 19

what is a thermal decomposition reaction

Answer 19

breaking down molecules by heating

Question 20

what are the two methods used for cracking

Answer 20

catalytic cracking and steam cracking

Question 21

what is the first step of cracking for both steps

Answer 21

heating the long chain hydrocarbon and vaporise them

Question 22

what does catalytic cracking use and what does this do

Answer 22

hot powdered aluminium oxide which the vapourised hydrocarbon will pass over splitting apart the hydrocarbon into two

Question 23

what does steam cracking use and what does this do

Answer 23

steam which gets mixed into the vapourised hydrocarbon causing it to split into two smaller ones

Question 24

what is the general balanced equation for the cracking of a long chain hydrocarbon

Answer 24

long chain hydrocarbon —– alkane + alkene

Question 25

why is one product of cracking an alkene

Answer 25

each side of the equation needs to be equal with the same amount of hydrogens and carbons. after cracking, there will be the correct amount of carbon but not enough hydrogens and therefore must form a double bond becoming an alkene

Question 26

Decane (C10H22) can be cracked into ethene ( C2H4) and one other hydrocarbon. write a balanced equation and find out the other product

Answer 26

C10H22 -------- ? + C2H4 need to be equal 10-2=8 22-4=18 ? = C8H18

Question 27

what is the general formular for an alkene

Answer 27

CnH2n

Question 28

what are the first four alkenes

Answer 28

ethene, propene, butene, pentene

Question 29

what are the formulars for the first four alkenes

Answer 29

C2H4 C3H6 C4H8 C5H10

Question 30

what do all alkenes have and what does this make them (think structure)

Answer 30

at least one double bond - unsaturated

Question 31

what are two differences of alkenes and alkanes

Answer 31

alkenes: - are more reactive and therefore react with bromine - they can be added together to make polymers

Question 32

how are alkenes made into polymers

Answer 32

double bonds can break to form two more bonds

Question 33

why can alkenes undergo addition reactions

Answer 33

they have a double bond which can open up and allow the two carbons to bond to atoms of other molecules

Question 34

what are the three types of addition reactions with alkenes

Answer 34

hydrogen, water, halogens

Question 35

explain what would happen in a reaction between propane and hydrogen

Answer 35

the double bond from the propane carbon atoms will break apart and the hydrogen atoms will be able to bond to the carbon. this forms the alkane propane which is now saturated

Question 36

what is the condition needed in the reaction between propane and hydrogen

Answer 36

a catalyst

Question 37

explain what would happen in a reaction between ethene and water

Answer 37

the double bond from ethene opens up and water molecules will split into hydrogen and O-H group and will bond. the product is then ethanol which is an alcohol

Question 38

what are the conditions needed in the reaction between ethene and water

Answer 38

a catalyst and high temperatures so that water can form a water vapour

Question 39

we have to separate the products of the reaction of ethene and water, these are ethanol, water and unreacted ethene. how do we do this

Answer 39

firstly cool it down to separate the unreacted ethene. the ethanol will stay a gas. use fractional distillation to separate the ethanol from the water

Question 40

explain what would happen in a reaction between an alkene and a halogen

Answer 40

same as the reaction with hydrogen just without the use of a catalyst

Question 41

explain what would happen in a reaction between ethene and bromine

Answer 41

will react and produce dibromoethane which will turn colourless from the orange colour

Question 42

what is the functional group of alcohols

Answer 42

OH

Question 43

what are the first four alcohols you must know

Answer 43

methanol, ethanol, propanol, butanol

Question 44

what is the general formular for an alcohol

Answer 44

CnH2n+OH

Question 45

what are the main properties for the first four alcohols

Answer 45

flammable, soluble, can be oxidised to form a carboxylic acid

Question 46

what does it mean when it is stated that an alcohol is flammable

Answer 46

it can undergo complete combustion

Question 47

what is the formular for the complete combustion of an alcohol (use ethanol) and balance

Answer 47

C2H5OH + 302 -------- 2CO2 + 3H2O

Question 48

what are the uses of alcohols that have undergone complete combustion

Answer 48

- used as fuels as they release a lot of energy - used as solvents in industry

Question 49

what is the functional group of a carboxylic acid

Answer 49

COOH

Question 50

what are the first four carboxylic acids

Answer 50

methanoic acid, ethanoic acid, propanoic acid, butanoic acid

Question 51

what are the first four carboxylic acid formulars

Answer 51

HCOOH, CH3COOH, C2H5COOH, C3H7COOH

Question 52

why are carboxylic acids referred to as weak acids

Answer 52

they don't fully ionise and therefore don't all release hydrogen ions

Question 53

what is the ionisation formular for a carboxylic acid (use propanoic acid)

Answer 53

C2H5COOH ------> C2H5COO- + H+ <------

Question 54

what are the products of the ionisation of propanoic acid

Answer 54

propanoate + hydrogen ion

Question 55

what is the general word formular for the reaction of a carboxylic acid with a metal oxide

Answer 55

carboxylic acid + metal oxide ---- salt + water + CO2

Question 56

what is the word equation for the reaction of ethanoic acid + potassium carbonate

Answer 56

ethanoic acid + potassium carbonate ------ potassium ethanoate + co2 + water

Question 57

how are carboxylic acids made

Answer 57

alcohol is oxidised using an oxidising agent agent to form a carboxylic acid

Question 58

what is the carboxylic acid of butanol

Answer 58

butanoic acid

Question 59

how are addition polymers made

Answer 59

the double bond from an alkane breaks up to form new bonds with each other forming a polymer

Question 60

write the equation for the addition polymerisation of butene ( C4H8)

Answer 60

H H H H H C2H5 \ | | | | | C = C -C - C - H rewrite as C = C / | | | | H H H H H H C2H5 H C2H5 | | | | n( C = C ) -------- -(- C - C -)- | | | | H H H H

Question 61

how do you name polymers

Answer 61

put word poly Infront of the monomer and put the monomer in brackets

Question 62

what is the functional group of an ester and where are esters found

Answer 62

COO - in the middle of a molecule

Question 67

what are two properties of esters

Answer 67

pleasant smell and are volatile

Question 67

how are esters made (use simple general word equation)

Answer 67

carboxylic acid + alcohol

Question 67

what type of catalyst is needed for an ester to be formed

Answer 67

an acid catalyst

Question 67

what happens to the carboxylic acid and alcohol to form an ester

Answer 67

the carboxylic acid looses its OH group and alcohol looses it's hydrogen from its OH group forming a water molecule

Question 68

polyesters usually use two different monomers to undergo condensation polymerisation, what are they

Answer 68

dicarboxylic acid and diol monomer

Question 69

what does dicarboxylic acid contain and draw the structure

Answer 69

contains 2 carboxylic acid group O O \\ / C - C / \ HO OH

Question 70

what do diol monomers contain and draw the structure

Answer 70

contains 2 alcohol groups H H | | HO - C - C - OH | | H H

Question 71

how do monomers combine in the process of condensation polymerisation

Answer 71

the dicarboxylic acid will give up an OH group and the diol monomer will give up a H from its OH group. these will form to make a water molecule. the carbon from the dicarboxylic acid will then bond with the oxygen from the diol. this bond is the ester link

Question 72

in order for molecules to combine in condensation polymers what do they need

Answer 72

- each monomer needs at least 2 functional groups - there needs to be 2 functional groups overall - a small molecule needs to be given up in the process - such as water

Question 73

why are polyesters biodegradable and why are these better than addition polymers

Answer 73

- bacteria and other small molecules is able to break down the ester link. these are better for the environment as addition polymers are mostly plastic and cant be broken down

Question 74

what are the three main naturally occurring polymers

Answer 74

polypeptides, DNA and carbohydrates

Question 75

what are polypeptides made up of

Answer 75

lots of amino acids

Question 76

what is DNA made up of

Answer 76

nucleartides

Question 77

what are carbohydrates made up of

Answer 77

sugars

Question 78

what happens if you take lots of amino acids and put them into a long chain

Answer 78

get a polypeptide which when folded up with other polypeptides added we get proteins

Question 79

what can different proteins do (generally)

Answer 79

catalyse chemical reactions as enzymes provide strength and structure to tissues

Question 80

what is the structure of amino acids and how can this be remembered better

Answer 80

H \ amino group = N / O H // carboxylic group = C \ OH joined together with carbon bond with R group which changes depending on amino acid remember - amino = amino group acid = carboxylic acid

Question 81

what does having two functional groups in an amino acid allow

Answer 81

allow other amino acids to join together through condensation reactions

Question 82

what are the four types of bases in DNA

Answer 82

T, A G, C

Question 83

when combing the different bases what can be created

Answer 83

genes

Question 84

how are DNA polymers protected from damage

Answer 84

they contain two polymer chains which link together which coils to form a double helix

Question 85

what are carbohydrate polymers made up from

Answer 85

carbon, oxygen and hydrogen

Question 86

what are the polymers in carbohydrates

Answer 86

starch, cellulose, glycogen

Question 87

what are the monomers in carbohydrates

Answer 87

glucose, fructose

Question 88

how do we make polymers form monomers

Answer 88

combining the monomers such as the glucose in long chains to make polymers such as starch