organic chemistry - C7

Question 1

how does boiling points, volatileness, viscosity and flammability change with the length of the carbon chain

Answer 1

smaller chains = lower boiling point, more volatile, more flammable
longer chains = higher boiling point, more viscous, less flammable

Question 2

how does fractional distillation work

Answer 2

-crude oil is heated at very high temperatures so that all the hydrocarbons evaporated
-its entered into a chamber and rises as its a gas
-hydrocarbons with higher boiling points condense at the bottom = bitumen, heavy fuel oil
-hydrocarbons with lower boiling points condense at the top = petrol, kerosene , diesel
-some are still gases by the top = LPG

Question 3

what is a feedstock?

Answer 3

a raw material used to provide reactants for industrial action

Question 4

what is a petrochemical?

Answer 4

as substance made from crude oil via chemical reactions

Question 5

why can alkenes do addition reactions?

Answer 5

because they have a double bond which can break apart so other molecules can be added

Question 6

how do alkenes react with hydrogen?

Answer 6

they form alkanes
its needs a catalyst to happen

Question 7

how do alkenes react with water?

Answer 7

they from alcohols
-the water splits up into hydrogen and hydroxide
-it needs a phosphoric acid catalyst and high temperatures

Question 8

how do we separate alcohol from water and an unreacted alkene

Answer 8

-alkene = heat up the alkene will evaporate
-water - fractional distillation, alcohol evaporates first (in the case of ethanol)

Question 9

how do alkenes react with halogens?

Answer 9

• they make halogenoalkanes
• no catalyst needed
• now considered alkane as there is no more double bond

Question 10

what is the bromine water test?

Answer 10

-alkenes will turn bromine water colourless
-alkanes will keep it orange

Question 11

what are the requirements for addition polymerisation reactions?

Answer 11

a catalyst and pressure

Question 12

why can’t alkanes do addition polymerisation reactions

Answer 12

they don’t have any double bonds

Question 13

what is the functional group for alcohols?

Answer 13

OH

Question 14

what are the properties of alcohols?

Answer 14

-flammable= can undergo complete combustion
-soluble - dissolve in water
- form carboxylic acids when oxidised

Question 15

what are the uses of alcohols?

Answer 15

fuels and solvents

Question 16

what is the uses of ethanol

Answer 16

chemical feedstock - to produce other organic compounds
-as a biofuel
-in alcoholic drinks

Question 17

how is ethanol produced with steam?

Answer 17

ethene + steam = ethanol

Question 18

what are the conditions needed for ethanol made from steam reaction

Answer 18

-high temperatures = 300 C
high pressures = 60 -70 atm
- phosphoric acid catalyst

Question 19

what are the advantages and disadvantages of ethanol reaction from steam

Answer 19

• its cheap and quick and efficient
  -ethene is non renewable as its made from crude oil

Question 20

how can ethanol be made from glucose

Answer 20

glucose = ethanol and carbon dioxide
this is fermentation = anaerobic respiration if yeast cells

Question 21

what are the the requirements needed to make ethanol from glucose?

Answer 21

• a fermentation tank
  -temperatures from 30 to 40 C as this is the optimum temperatures for the enzymes
  -no oxygen

Question 22

what are the pros and cons of making ethanol from glucose

Answer 22

• glucose is renewable, yeast is easy to grow
• the reaction is slow, the ethanol isn’t pure and has to be distilled

Question 23

how are carboxylic acids formed ?

Answer 23

by oxidising an alcohol

Question 24

what is the functional group for carboxylic acids?

Answer 24

COOH

Question 25

why are carboxylic acids weak acids

Answer 25

they do not fully ionise in water = they do not release all of their hydrogen ions their reaction with water is reversible they from "anoate" ions and a hydrogen ion

Question 26

what is formed when a carboxylic acid reacts with a metal carbonate

Answer 26

salt, water, carbon dioxide

Question 27

how are esters formed

Answer 27

carboxylic acid and alcohol

Question 28

what are the properties of an ester

Answer 28

flammable and volatile

Question 29

what are esters used in

Answer 29

perfumes and food flavourings

Question 30

what is the functional groip for esters

Answer 30

COO

Question 31

How do carboxylic acids and alcohols change to make esters

Answer 31

the carboxylic acid loses its OH group the alcohol loses its H from it Oh group this forms an ester and water as as a by product

Question 32

what can the ester functional group be called

Answer 32

-ester group -ester link -ester bond

Question 33

what is required to make esters

Answer 33

an acid catalyst , usually a sulphuric acid catalyst

Question 34

how are polyesters formed with condensation polymerisation

Answer 34

with dicarboxylic acids and diols

Question 35

what are to bonded monomers called

Answer 35

dimers

Question 36

what is required for polyester condensation polymerisation to happen

Answer 36

two functional groups in each monomer

Question 37

how is the polyester formed

Answer 37

the dicarboxylic acid loses its OH and the diol loses it H to form water -this allows the two to join together to form a dimer -to make it a repeating unit the dicarboxylic acid will lose another OH and the diol will lose another H to form another water -now they're are two waters

Question 38

what will ethanoic acid and propanediol form

Answer 38

poly(propyl ethanoate)

Question 39

what is a monomer

Answer 39

a molecule that can be bonded to other identical molecules to form a polymer

Question 40

what is a polymer

Answer 40

a large, long chain of molecules made by linking smaller molecules together

Question 41

why is it called condensation polymerisation?

Answer 41

because water is produced just like gaseous water condenses to produce water

Question 42

why are condensation polymers biodegradable?

Answer 42

because microorganisms can break the ester link

Question 43

what is the general formula for alcohols

Answer 43

CN H2N+1 OH

Question 44

what is the general formula for carboxylic acids

Answer 44

CN H2N+1 COOH

Question 45

what is a polypeptide (polymer)

Answer 45

a long chain of amino acids(monomer)

Question 46

what groups are present in an amino acid

Answer 46

carboxyl group (COOH) amino group (NHH) R group (changes depending on amino acid)

Question 47

how are polypeptides formed

Answer 47

through condensation polymerisation -one amino acid loses its OH from the carboxyl group -another loses on H from the amino group -this means the carbon and nitrogen bond -water is formed as a by product

Question 48

what is the bond between nitrogen and carbon in a polypeptide called

Answer 48

amide bond amide link peptide bond

Question 49

what is the monomer that make DNA

Answer 49

nucleotides

Question 50

what are the bases in nucleotides?

Answer 50

A,T,C,G

Question 51

what is the DNA structure

Answer 51

2 long chains of polymers that naturally coil up to form a double helix

Question 52

why do the polymers strands coil up

Answer 52

to protect the DNA from damage

Question 53

what are carbohydrates made up of

Answer 53

carbon, hydrogen and oxygen

Question 54

what polymer carbohydrates are there

Answer 54

glycogen, cellulose, starch

Question 55

what carbohydrate monomers are there

Answer 55

glucose and fructose