organic chemistry

Question 1

how are condensation polymers made

Answer 1

using ester links

Question 2

what do carbons mostly bond to

Answer 2

hydrogen and carbon themselves

Question 3

what are the first 4 alkanes

Answer 3

methane
ethane
propane
butane

Question 4

what is the meaning of homologous series and give an example

Answer 4

groups of organic compounds/molecules that react in a similar way and have similar chemical properties
Same functional group / same general formula / differ by CH2

eg alkanes

Question 5

formula for alkanes

Answer 5

CnH2n+2

Question 6

why do we refer to alkanes as saturated

Answer 6

no double bonds- every carbon atom has 4 single covalent bonds and are all bonded to something

Question 7

what is a hydrocarbon

Answer 7

A hydrocarbon is a molecule that only contains the elements carbon and hydrogen hydrogen.

Question 8

What are trends of alkanes as you go down the group

Answer 8

boiling point increases
volatility decrease
viscosity increases
flammability decreases

Question 9

what is the equation for complete combustion

Answer 9

hydrocarbon+oxygen> carbon dioxide+water

Question 10

why do we say complete combustion is an exothermic reaction

Answer 10

it releases a lot of energy

Question 11

what is being oxidised in complete combustion

Answer 11

carbon and hydrogen

Question 12

what is crude oil

Answer 12

a fossil fuel found deep underground with mainly hydrocarbons(mainly alkanes)

Question 13

how is crude oil formed

Answer 13

Crude oil is formed from the remains of dead plants and animals, particularly plankton.
These organic remains were covered by mud and sand, and buried in the earth.
Over millions of years, these organic remains were compressed under a lot of heat and pressure.
The heat and pressure chemically changed the organic remains into crude oil

Question 14

what is fractional distillation

Answer 14

heating and seperate different compunds

Question 15

what are the steps of fractional distillation

Answer 15

feed oil into chamber and heat it until most oil has turned into gas

pass gaseous mixture into fractionating column(which is hot at the bottom and cools down at top)

when the hot gases reach a region that is cooler than their boiling point they condense into a liquid

Question 16

what happens to short chain hydrocarbons vs long in fractional distillation

Answer 16

long-quickly condense back into liquid and drain out right away(eg bitumen/heavy fuel oil and can be seperated further into heating oil/fuel oil)

short-rise up much more(diesel/petrol and kerosene

very short- stay as gas entire time(lpg)

Question 17

why are the shorter chain hc better fuels

Answer 17

they are more flammable

Question 18

what is a feedstock

Answer 18

A feedstock is a raw material used to provide reactants for an industrial reaction.

Question 19

what is a petrochemical

Answer 19

A petrochemical is a substance made from crude oil, via chemical reactions.

Question 20

what is the relation between feedstocks and petrochemicals

Answer 20

So basically, the different hydrocarbons in crude oil are all feedstocks, but the useful things we then make from those hydrocarbons (polymers, solvents, lubricants, detergents etc.), are all petrochemicals.

Question 21

what is cracking

Answer 21

a thermal decompostion reaction where longer less useful hc are broken down into shorter more useful/flammable hc

Question 22

what are the 2 methods of cracking

Answer 22

catalytic and steam cracking

Question 23

what are the steps in catalytic cracking

Answer 23

heat long chain hydrocarbons and vapourise them

use hot powdered aluminium oxide as catalyst passing vapour over powder splitting them apart into 2 smaller hc

Question 24

what are the steps of steam cracking

Answer 24

heat and vapourise hydrocarbons to
mix them with steam
heat them to very high temps causing them to split

Question 25

what is the difference between alkenes and alkanes

Answer 25

allkenes unsaturated -have double bond making them more reactive than alkanes react with bromine water changing it from orange to colourless form polymers

Question 26

alkene addition reaction with hydrogen

Answer 26

alkene+hydrogen gas>alkane +catalyst

Question 27

addition reaction with water

Answer 27

alkene+water(steam/vapour)>alcohol +catalyst and high temps

Question 28

alkene+halogen=

Answer 28

alkene+halogen>dibromo-alkane

Question 29

how do we name addition polymers

Answer 29

put "poly" in front of monomer

Question 30

what do addition polymerisation reactions require

Answer 30

high pressure and catalysts to work

Question 31

what makes alcohols different to alkanes

Answer 31

an oh functional group

Question 32

what is the general formula for alcohol

Answer 32

CnH2n+1

Question 33

what are the properties of the 1st 4 alcohols

Answer 33

flammable soluble oxidise to form carboxylic acids

Question 34

alcohol+oxygen

Answer 34

=co2 + water

Question 35

uses of alcohols

Answer 35

can be used as fuels(release a lot of energy) as solvents in industry (can dissolve fats and oils that water cant)

Question 36

what are the uses of ethanol

Answer 36

As a chemical feedstock to produce other organic compounds. As a biofuel (ethanol can be burned like petrol). Used in alcoholics drinks such as beer, wine, and spirits

Question 37

what is a comercial way ethanol is produced/pros and cons/conditions

Answer 37

ethene+steam high temp/catalyst/high pressure (300 degrees)/phosphoric acid/60-70 atm this reaction is cheap and efficient ethene is finite/will become expensive if used up

Question 38

what is another way to produce ethanol/pros and cons/conditions

Answer 38

fermentation(anaerobic respiration of sugars by yeast cells to produce ethanol and c02 must be in fermentation tanks at temp of 30-40 and must be anaerobic so ethanol isnt oxidised to ethanoic acid glucose is renewable and yeast is easy to grow process is slow and ethanol made isnt purre so must be further purified/ distilled in fractional distillation

Question 39

what is the functional group of carboxylic acids(homologous series)

Answer 39

cooh/names all end in -anoic acid

Question 40

are carboxylic acids strong or weak

Answer 40

weak

Question 41

what are the - ions that carboxylic acids form

Answer 41

anoate

Question 42

carboxylic acid +metal carbonate

Answer 42

water, salt and carbon dioxide

Question 43

how are carboxylic acids made

Answer 43

taking an alcohol and oxidising it with an oxidising agent

Question 44

carboxylic acids reaction with metal/metal hydroxide

Answer 44

Carboxylic acid + metal ➔ salt + hydrogen Carboxylic acid + metal oxide ➔ salt + water Carboxylic acid + metal hydroxide ➔ salt + water

Question 45

what is the functional group of esters

Answer 45

coo in the middle

Question 46

what are properties of esters

Answer 46

volatile nice/fruit smelling

Question 47

how do we make esters

Answer 47

carboxylic acids+alcohol>ester+water (acid catalyst)(sulfuric acid)

Question 48

what is the only ester you need to know how to form

Answer 48

Ethanoic acid + ethanol ➔ Ethyl ethanoate

Question 49

how are polyesters made

Answer 49

with dicarboxylic acid monomers(2 carboxylic acid groups) + diol monomers(2 alcohol groups)

Question 50

what is given up when making condensation polymers

Answer 50

dicarboxylic acid monomer gives up oh group and diol gives up h forming a water molecule this leaves carbon from dicarboxylic acids carbon to react with the oxygen of the diol monomer the ester link

Question 51

for molecules to combine in condensation polymers what is required

Answer 51

each monomer must have at least 2 functional groups must be 2 different functional groups overall must be a small molecule given off

Question 52

what do the boxes in the middle of the monomers represent

Answer 52

the rest of the molecule in simplified form

Question 53

what is a dimer

Answer 53

2 monomers combined

Question 54

When is a polymer referred to as a 'condensation' polymer?

Answer 54

When water is a produced as a by-product of the reaction

Question 55

what types of polymers are biodegradable and why

Answer 55

condensation as ester links can be broken down by microorganisms

Question 56

what groups do all amino acids have

Answer 56

carboxyl group and amino group(h-n-h)

Question 57

how do amino acids join to form polymers

Answer 57

through condensation reactions when bottom right oh from carboxyl group and bottom left h from amino group react producing water and allowing carbon and nitrogen to bond together(called amide bond/peptide bond)

Question 58

what are the monomers in dna

Answer 58

structures called nucleotides which contain bases(t a g c) -basically 4 types

Question 59

what are genes

Answer 59

these nucleotides arranged in different orders

Question 60

how/why does the double helix structure form

Answer 60

the 2 polymer chains link together coiling naturally to keep the genes intact and prevent damage

Question 61

what are the elements that make up carbs

Answer 61

carbon,oxygen and hydrogen

Question 62

what are carb polymers and what are they called

Answer 62

polyssacharides like starch,cellulose and glycogen

Question 63

what is the general meaning of carbs

Answer 63

number of polymers and monomers we derive energy from

Question 64

what are the monomers of carbs called

Answer 64

monosaccharides like glucose or fructose

Question 65

what monomers combine to form a polypeptide

Answer 65

amino acids

Question 66

What do polypeptides form once they fold up?

Answer 66

protein