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Hint
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Answer
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what is alkanes general formula
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CₙH₂ₙ₊₂
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what is n in the general formula
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number of carbon atoms
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how do alkanes react with halogens
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in the presence of UV radiation like the sun
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describe the reaction between bromine and methane and state the word equation
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methane reacts with bromine in the presence of UV light, here a hydrogen atom from the methane is replaced by a bromine atom, this is a substitution reaction.
methane + bromine ─> bromomethane + hydrogen bromide |
alkanes react with bromine in the presence of UV light, here a hydrogen atom from the methane is replaced by a bromine atom, this is a substitution reaction
methane + |
carbon dioxide, water and heat energy
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what is alkenes general formula
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CₙH₂ₙ
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what are alkenes functional group
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C=C
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how do alkenes react with halogens
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doesn't need UV radiation |
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describe the reaction between ethene and bromine and state the word equation
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ethene reacts with bromine without UV light, here the double bond is broken and bromine atoms are added, this is an addition reaction. We see a colour change from orange to colourless if the reaction has occurred
ethene + bromine ─> dibromoethene |
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what colour is dibromoethene in liquid form
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colourless
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what colour is bromine in liquid form
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orange
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how do we test for alkanes and alkenes
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in the absence of UV light, we add our unknown solution to bromine water, if a reaction doesn't happen then it probably contains an alkane as alkanes need UV light to react with a halogen. Then we add another unknown solution and if it contains alkenes it will turn from orange to colourless as alkenes can react with a halogen without UV light.
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what is an alcohol
(don't say homologous series, general formula or functional group.) |
a hydroxyl attached to a hydrocarbon chain
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what's a carboxyl
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-COOH ( carboxylic acid functional group)
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what's a hydroxyl
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-OH (alcohol functional group)
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state the structural formula of pent-2-anol |
CH₃-CH-OH-CH₂-CH₂-CH₃
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what does ethanol produce when it's oxidised by complete combustion
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carbon dioxide and water
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what does ethanol produce when it's oxidised by microorganisms
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ethanoic acid
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what are the three main ways to oxidise ethanol
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complete combustion microbial oxidation heating with an oxidising agent |
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how do you oxidise ethanol using potassium dichromate (VI) in sulfuric acid
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mixture starts orange, and when the reaction happens the mixture turns green, this indicates Cr³⁺ ions are present, which is formed when potassium dichromate (VI) is reduced
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describe the hydration of ethene and state the conditions and word equation
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ethanol is made by passing ethene and steam over a catalyst. Water is added to ethene, which is why it's called hydration, use a phosphoric acid catalyst at a temperature of around 300°C and a pressure of about 60-70 atm.
Ethene + Water ───────────> Ethanol ............................phosphoric acid |
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what's fermentation
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conversion of sugar into ethanol using enzymes in yeast
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describe fermentation and state the conditions and word equation
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ethanol is made by mixing the catalyst found in yeast with a sugar solution at a temperature of 30-40°C and a pressure of just below 1 atm. It is done in the abscene of oxygen.
Glucose ────────> ethanol + carbon dioxide ..................zymase |
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why is fermentation carried out anaerobically
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if it was done aerobically then it would produce water and carbon dioxide and ethanol wouldn't be produced. If it is done anaerobically it would produce ethanol and carbon dioxide, and this ethanol produced can react with oxygen to form ethanoic acid.
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why is fermentation carried out at a low temperature
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because if it was done higher it would denature the enzymes from the yeast, stopping them catalysing the reaction, but if too low then the reaction is too slow.
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name the advantages of fermentation
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cheap ─ as little energy is needed uses a renewable resource ─ so it can happen forever |
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name the disadvantages of fermentation
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slow ─ temperature is too low so particles have little kinetic energy doesn't produce pure ethanol ─ have to fractionally distil it to get it pure which is slow and expensive |
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name the disavantages of the hydration of ethene
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expensive ─ lots of energy is needed uses a non renewable resource ─ so it will run out |
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name the advantages of the hydration of ethene
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continuous process ─ little workers needed fast ─ happens at high temperatures and pressures |
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what are carboxylic acids functional group
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-COOH
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what are carboxylic acids general formula
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CₙH₂ₙ₊₁COOH
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name the 5 main homologous series in alphabetical order
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alcohols, alkanes, alkenes, carboxylic acids and esters |
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what is the carboxyl group (draw it)
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what is the hydroxyl group (draw it)
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O-H
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what is the rule when writing carboxylic acids structural formula
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always write the -COOH at the end of the structural formula
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what is the rule when drawing carboxylic acids displayed formula
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always draw the -COOH first and then draw the rest
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what is vinegar
(include ethanoic acid in answer) |
an aqueous solution containing ethanoic acid
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do dilute carboxylic acids react like other dilute acids but just slower
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yes
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dilute carboxylic acid + metal =.....
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salt + hydrogen gas
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dilute carboxylic acid + carbonate =....
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water + salt + carbon dioxide
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describe the reaction between ethanoic acid and magnesium
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ethanoic acid reacts with magnesium with lots of fizzing to produce a colourless solution of magnesium ethanoate and hydrogen gas
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describe the reaction between ethanoic acid and sodium carbonate
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ethanoic acid reacts with sodium carbonate with lots of fizzing to produce a colourless solution of sodium ethanoate, water and carbon dioxide.
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in the reaction between ethanoic acid and sodium carbonate why is the charge on the resulting ethanoate ion -1
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because it's lost an electron from the hydrogen atom, which goes off to from water
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what are esters functional group
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-COO
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what is the ester link (draw it)
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what is the ester link
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esters functional group
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what is a volatile liquid
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one that turns into vapour easily
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what are esters usually used in
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perfumes and food colourings
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what characterises an ester using one of our 5 senses
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their fruity, sweet, distinctive smells
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how are esters made
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when a carboxylic acid reacts with an alcohol
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what is the ester made when ethanol and ethanoic acid react
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ethyl ethanoate
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how do we name an ester
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first part of the name comes from the alcohol, where -ano is replaced with a y.
second part of the name comes form the carboxylic acid, where -ic acid is replaced with -ate. |
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what is ethyl ethanoate's structural formula
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CH₃COOCH₂CH₃
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how do you draw an esters displayed formula
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first get the carboxylic acid and the alcohol that it's made of and draw their displayed formula. Draw the -OH on the left of the alcohol and the -COOH on the right of the carboxylic acid, draw the carboxylic acid on the left and alcohol on the right so both their groups are beside each other. Remove the H from the OH and the OH from the COOH, this forms water. Re draw the alcohol and carboxylic acid but this time without the removed atoms. Join the oxygen with the carbon atom and we're done.
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describe the reaction between ethanoic acid and ethanol
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ethanol and ethanoic acid are heated to form liquid ethyl ethanoate and water in the presence of a few drops of concentrated sulfuric acid. This reaction is called esterification. It's also called a condensation reaction because 2 molecules have reacted to give water. The reaction is reversible as well. Pure reactants are used to maximise the yield of ethyl ethanoate.
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what is glacial ethanoic acid
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pure ethanoic acid
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the name of an ester is the carboxylic acid first and the alcohol second
true or false |
false
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the structural and displayed formula has the alcohol first and the carboxylic acid second
true or false |
false
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what's an addition polymer
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when the same monomers join together to form one large polymer
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how is an addition polymer made
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one of the bonds in the double bond breaks in every monomer, these monomers then join together in a large chain
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what are the monomers in an addition polymer
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alkenes
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what types of bonds does an addition polymer have
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single bonds
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what is a condensation polymer
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when two different monomers join in an alternating pattern to form a large polymer and another small molecule
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how is a condensation polymer made
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formed from a condensation reaction
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what are the two different monomers in a condensation polymer
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diols and dicarboxylic acids
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what is a polyester
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a polymer formed when 2 different monomers join in an alternating pattern
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finish the sentence
when each monomer joins to the next in a condensation polymer a separate..... |
small molecule is lost
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what are the small molecules formed in a condensation polymerisation reaction usually
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water molecules or hydrogen chloride
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when a condensation polymer is formed what is the reaction called
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condensation polymerisation reaction
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what is a diol
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an alcohol with -OH on either side of it
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what is a dicarboxylic acid
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a carboxylic acid with -COOH on either side of it
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what is the only thing present in a diol that is important for polymerisation
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-OH functional group
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what is the only thing present in a dicarboxylic acid that is important for polymerisation
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-COOH functional group
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what does the box in this diol simplified displayed formula represent:
HO─▅─HO |
the central block of carbon atoms
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what does the box in this dicarboxylic acid simplified displayed formula represent:
..... O.......... O .......‖............‖ HO-C─▅─C-OH
(ignore the dots) |
the central block of carbon atoms
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why are polymers inert
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because they have strong C-C bonds
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what is the result of polymers being inert
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they are non─biodegradeable
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what does biodegradeable mean
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breakdown of a substance by microorganisms
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what is the ester functional group called
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ester link
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define a polyester using the phrase ester link
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a polyester is a long chain containing many ester links
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in the ester link, where does the C=O bond come from
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carboxylic acid
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in the ester link, where does the O come from
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alcohol
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if an addition polymer is burnt what happens
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could produce toxic gases like hydrogen chloride or carbon monoxide
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why are the environmental issues with the disposal of condensation polymers less severe than with addition polymers
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because of their ester links they can be broken down, making them biodegradeable
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out of the 2 polymers, what has a more harmful effect when broken down
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addition polymers
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how long do condensation polymers take to breakdown
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can take hundreds of years
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what polyesters have chemists recently made and why are they good
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biopolyesters which break down much faster
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how do you turn the monomer unit into a repeating unit
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first put single bonds on either side of the C=C, put brackets around it and draw the single bonds on either side of the C=C coming out of the brackets, re draw the double bond as a single bond, put an n in subscript on the bracket which represents the number of monomers.
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how do you name an addition polymer from it's monomer
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first write poly and put brackets around the monomers name
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what is the polymer poly(ethene) derived from
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ethene
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when tetrafluoroethene monomers join together what addition polymer is produced
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poly(tetrafluoroethene) or PTFE
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when chloroethene monomers join together what is the addition polymer produced
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poly(chloroethene) or PVC
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what is PTFE
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poly(tetrafluoroethene)
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what is PVC
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poly(chloroethene)
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