Organic Chemistry 2 Flashcards
How can ethanol be made using fermentation + conditions?
fermentation of aqueous glucose
25–35°C
in the presence of yeast
in the absence of oxygen
How can ethanol be made using ethene + conditions?
catalytic addition of steam to ethene
300°C
60 atm
acid catalyst
Describe the combustion of ethanol.
- burns readily with an almost invisible blue flame
- burns cleanly and without strong odours
ethanol + oxygen -> water + carbon dioxide
Uses of ethanol
SOLVENT
FUEL
miss americana
and the heartbreak prince
Why is ethanol used in cosmetics?
it is safe for human contact
Describe the advantages of the manufacture of ethanol by fermentation.
uses crops and waste plant material, which is a sustainable source
can be conducted at low temperatures so is a relatively inexpensive process
Describe the disadvantages of the manufacture of ethanol by fermentation.
use of crops for fermentation could impact on food supply
requires ethanol to be produced in batches so it is a stop-start process
requires the impure product to be refined by fractional distillation
Describe the advantages of the manufacture of ethanol by the catalytic addition of steam to ethene.
can produce ethanol continuously to meet market demands
can produce ethanol in a fully automated factory requiring little input from human workers
can yield pure ethanol that does not need further refinement
Describe the disadvantages of the manufacture of ethanol by the catalytic addition of steam to ethene.
uses petroleum from fossil fuels, which will eventually run out
requires high temperatures and pressure, which is expensive
Describe the reaction of ethanoic acid with metals
forms salts that contain the ethanoate ion, CH3COO–
bubbles of hydrogen gas are seen
Describe the reaction of ethanoic acid with bases
forms salt and water
salt contains ethanoate ion CH3COO-
Describe the reaction of ethanoic acid with carbonates
acid + carbonate → salt + water + carbon dioxide
bubbles of CO2 seen
forms salt with ethanoate ion CH3COO-
In which two ways can ethanoic acid be made?
oxidation of ethanol with acidified aq. potassium manganate (VII)
oxidation of ethanol by bacterial oxidation during vinegar production
How can ethanoic acid be made with acidified aq. potassium manganate (VII)?
KMnO4 is a strong oxidising agent, used in the presence of sulfuric acid and heat
produces ethanoic acid from ethanol
How can ethanoic acid be made by bacterial oxidation?
Bacteria such as acetobacter contain enzymes that catalyse the oxidation of ethanol to ethanoic acid and water
carboxylic acid + alcohol
forms an ester
uses an acid catalyst
Define polymers
large molecules built up from
many smaller molecules called monomers
Describe the formation of poly(ethene)
addition polymerisation
many ethene monomer molecules react together, joining end to end to make poly(ethene) molecules
no other product forms
example of addition polymerisation
formation of poly(ethene) using ethene monomers
Deduce the structure or repeat unit of an addition polymer from a given alkene
change the C=C bond in the monomer into a C–C bond
draw a line from each of the C atoms that were in the C=C bond (representing covalent bonds between repeat units)
draw brackets around the repeat unit
Polyamides
condensation polymers
made from a dicarboxylic acid and a diamine
What is a dicarboxylic acid
molecule that contains two COOH groups
diamine
a molecule that contains two NH2 groups
how to draw polyamides/formation
carbon chain between the two functional groups is shown as a rectangle
two monomers react with other’s functional group, and a molecule of water is eliminated each time a bond forms
a dicarboxylic acid and a diamine form
a polyamide
polyesters are formed from
a dicarboxylic acid and a diol
a dicarboxylic acid and a diol form
polyesters
what is a diol
a molecule that contains two OH groups
formation of polyesters, drawn
Differences between addition and
condensation polymerisation.
In a condensation reaction, unlike addition reactions a smaller molecule is also produced (usually water)
Describe and draw the structure of nylon
polyamide
Describe and draw the structure of PET
polyester
what are plastics made from?
polymers
properties of plastics and their consequences
takes an extremely long time to decompose
what are the environmental challenges caused by plastics
disposal in landfill sites
accumulation in oceans
formation of toxic gases from burning
describe the environmental challenge caused by plastic disposal in land fill sites
suitable land for new sites is becoming difficult to find, existing sites eventually fill up.
problem of plastic pollution does not go away once it is buried.
- as the plastics break down, some particles can be washed out with the ground water, contaminating the surrounding area and nearby streams and rivers
describe the environmental challenge caused by plastic burning
toxic gases may form
what makes PET extra useful
it can be converted back into
monomers and re-polymerised
What are proteins
natural polyamides, formed from amino acid monomers
general structure of amino acids
contains an NH2 and a COOH group
R represents different types of side chain
describe and draw the structure of proteins
