organic chemistry - C7 Flashcards
how does boiling points, volatileness, viscosity and flammability change with the length of the carbon chain
smaller chains = lower boiling point, more volatile, more flammable
longer chains = higher boiling point, more viscous, less flammable
how does fractional distillation work
-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
what is a feedstock?
a raw material used to provide reactants for industrial action
what is a petrochemical?
as substance made from crude oil via chemical reactions
why can alkenes do addition reactions?
because they have a double bond which can break apart so other molecules can be added
how do alkenes react with hydrogen?
they form alkanes
its needs a catalyst to happen
how do alkenes react with water?
they from alcohols
-the water splits up into hydrogen and hydroxide
-it needs a phosphoric acid catalyst and high temperatures
how do we separate alcohol from water and an unreacted alkene
-alkene = heat up the alkene will evaporate
-water - fractional distillation, alcohol evaporates first (in the case of ethanol)
how do alkenes react with halogens?
- they make halogenoalkanes
- no catalyst needed
- now considered alkane as there is no more double bond
what is the bromine water test?
-alkenes will turn bromine water colourless
-alkanes will keep it orange
what are the requirements for addition polymerisation reactions?
a catalyst and pressure
why can’t alkanes do addition polymerisation reactions
they don’t have any double bonds
what is the functional group for alcohols?
OH
what are the properties of alcohols?
-flammable= can undergo complete combustion
-soluble - dissolve in water
- form carboxylic acids when oxidised
what are the uses of alcohols?
fuels and solvents
what is the uses of ethanol
chemical feedstock - to produce other organic compounds
-as a biofuel
-in alcoholic drinks
how is ethanol produced with steam?
ethene + steam = ethanol
what are the conditions needed for ethanol made from steam reaction
-high temperatures = 300 C
high pressures = 60 -70 atm
- phosphoric acid catalyst
what are the advantages and disadvantages of ethanol reaction from steam
- its cheap and quick and efficient
-ethene is non renewable as its made from crude oil
how can ethanol be made from glucose
glucose = ethanol and carbon dioxide
this is fermentation = anaerobic respiration if yeast cells
what are the the requirements needed to make ethanol from glucose?
- a fermentation tank
-temperatures from 30 to 40 C as this is the optimum temperatures for the enzymes
-no oxygen
what are the pros and cons of making ethanol from glucose
- glucose is renewable, yeast is easy to grow
- the reaction is slow, the ethanol isn’t pure and has to be distilled
how are carboxylic acids formed ?
by oxidising an alcohol
what is the functional group for carboxylic acids?
COOH
why are carboxylic acids weak acids
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
what is formed when a carboxylic acid reacts with a metal carbonate
salt, water, carbon dioxide
how are esters formed
carboxylic acid and alcohol
what are the properties of an ester
flammable and volatile
what are esters used in
perfumes and food flavourings
what is the functional groip for esters
COO
How do carboxylic acids and alcohols change to make esters
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
what can the ester functional group be called
-ester group
-ester link
-ester bond
what is required to make esters
an acid catalyst , usually a sulphuric acid catalyst
how are polyesters formed with condensation polymerisation
with dicarboxylic acids and diols
what are to bonded monomers called
dimers
what is required for polyester condensation polymerisation to happen
two functional groups in each monomer
how is the polyester formed
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
what will ethanoic acid and propanediol form
poly(propyl ethanoate)
what is a monomer
a molecule that can be bonded to other identical molecules to form a polymer
what is a polymer
a large, long chain of molecules made by linking smaller molecules together
why is it called condensation polymerisation?
because water is produced just like gaseous water condenses to produce water
why are condensation polymers biodegradable?
because microorganisms can break the ester link
what is the general formula for alcohols
CN H2N+1 OH
what is the general formula for carboxylic acids
CN H2N+1 COOH
what is a polypeptide (polymer)
a long chain of amino acids(monomer)
what groups are present in an amino acid
carboxyl group (COOH)
amino group (NHH)
R group (changes depending on amino acid)
how are polypeptides formed
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
what is the bond between nitrogen and carbon in a polypeptide called
amide bond
amide link
peptide bond
what is the monomer that make DNA
nucleotides
what are the bases in nucleotides?
A,T,C,G
what is the DNA structure
2 long chains of polymers that naturally coil up to form a double helix
why do the polymers strands coil up
to protect the DNA from damage
what are carbohydrates made up of
carbon, hydrogen and oxygen
what polymer carbohydrates are there
glycogen, cellulose, starch
what carbohydrate monomers are there
glucose and fructose
