4 Addition polymers

 

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4.1.3 alkenes Page 5

Oxford Textbook Pages : 215 - 219

CGP Revision Guide Pages : 98 - 99

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Show Specification Ref : 4.1.3j, 4.1.3k, 4.1.3l

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Question 1 / 5

AQA Jun 2010 Paper 2 Q9 do not write outside the box the method of extraction of zinc has changed as different ores containing the element have been discovered and as technology has improved extraction process in the earliest process calamine impure zinc carbonate was heated with charcoal in earthenware pots this two stage process gave a low yield of zinc znco s zno s c s zno s co g zn s co g extraction process deposits of calamine were being used up and a new two stage process was developed using zinc sulfide ores all of the waste gases from this process were released into the atmosphere zns s o g zno s c s zno s so g zn s co g extraction process the modern process uses the electrolysis of aqueous solutions of very pure zinc sulfate the first step in this process is the same as the first step in extraction process the second step uses sulfuric acid made from the so collected in the first step the third step involves the electrolysis of zinc sulfate solution to form pure zinc zns s o g zno s h so aq zno s so g znso aq h o i znso aq electrolysis zn s a in the first stage of extraction process the following equilibrium is established when zinc carbonate is heated in a closed container znco s zno s co g use le chatelier s principle to suggest and explain the effect on the yield of zinc oxide of allowing the carbon dioxide to escape from the container marks extra space wmp jun chem do not write outside the box b state and explain one environmental reason why extraction process is an improvement over extraction process marks extra space c give one reason why extraction process is an expensive method of making zinc but one which is justified in terms of the product formed marks extra space question continues on the next page turn over wmp jun chem do not write outside the box d deduce the half equation for the formation of zinc from zinc ions during the electrolysis of zinc sulfate solution and identify the electrode at which this reaction occurs marks extra space e identify one reaction from the three extraction processes that is not a redox reaction and state the type of reaction that it is in terms of redox state what happens to the carbon in extraction process marks extra space wmp jun chem do not write outside the box f zinc and magnesium both react with steam in a similar way write an equation for the reaction of zinc with steam and name the products of this reaction marks extra space end of questions wmp jun chem
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Question 2 / 5

AQA Jun 2012 Paper 2 Q8 section b answer all questions in the spaces provided do not write outside the box the reaction of butane diol with butanedioic acid produces the polymer pbs used in biodegradable packaging and disposable cutlery butanedioic acid is produced by two different processes process l aqueous sodium hydroxide reacts with dibromobutane to make butane diol l butane diol is oxidised to butanedioic acid process l glucose reacts with carbon dioxide in the presence of microorganisms to produce butanedioic acid directly l the carbon dioxide used in this process is obtained from a local factory that produces bioethanol a deduce one safety reason and one environmental reason why process is preferred to process marks extra space wmp jun chem do not write outside the box b i name and outline a mechanism for the following reaction that occurs in process brch ch ch ch br naoh brch ch ch ch oh nabr marks question continues on the next page turn over wmp jun chem do not write outside the box b ii the infrared spectra shown are those of three compounds compound a dibromobutane compound b butane diol compound c butanedioic acid identify the compound responsible for each spectrum by writing the correct letter a b or c in the box next to each spectrum you may find it helpful to refer to table on the data sheet transmittance wavenumber cm transmittance wavenumber cm transmittance wavenumber cm marks wmp jun chem do not write outside the box c in the production of bioethanol glucose c h o is converted into a dilute aqueous solution of ethanol and carbon dioxide give the name of this process and state three essential conditions necessary to produce a good yield of ethanol marks extra space d state the class of alcohols to which the diol butane diol belongs identify a suitable reagent or combination of reagents for the conversion of butane diol into butanedioic acid hoocch ch cooh write an equation for this oxidation reaction using o to represent the oxidising agent marks extra space turn over wmp jun chem
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Question 3 / 5

AQA Jun 2014 Paper 2 Q3 do not write outside the box a antimony is a solid element that is used in industry the method used for the extraction of antimony depends on the grade of the ore antimony can be extracted by reacting scrap iron with low grade ores that contain antimony sulfide sb s a i write an equation for the reaction of iron with antimony sulfide to form antimony and iron ii sulfide mark a ii write a half equation to show what happens to the iron atoms in this reaction mark b in the first stage of the extraction of antimony from a high grade ore antimony sulfide is roasted in air to convert it into antimony iii oxide sb o and sulfur dioxide b i write an equation for this reaction mark b ii identify one substance that is manufactured directly from the sulfur dioxide formed in this reaction mark wmp jun chem do not write outside the box c in the second stage of the extraction of antimony from a high grade ore antimony iii oxide is reacted with carbon monoxide at high temperature c i use the standard enthalpies of formation in table and the equation given below table to calculate a value for the standard enthalpy change for this reaction table sb o s co g hf kj mol sb i co g sb o s co g sb i co g marks c ii suggest why the value for the standard enthalpy of formation of liquid antimony given in table is not zero mark c iii state the type of reaction that antimony iii oxide has undergone in this reaction mark d deduce one reason why the method of extraction of antimony from a low grade ore described in part a is a low cost process do not include the cost of the ore mark turn over wmp jun chem
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Question 4 / 5

AQA Jun 2011 Paper 4 Q5 do not write outside the box items softened with plasticisers have become an essential part of our modern society compound s shown below is commonly known as phthalic acid esters of phthalic acid are called phthalates and are used as plasticisers to soften polymers such as pvc poly chloroethene cooh cooh a give the iupac name for phthalic acid mark b draw the displayed formula of the repeating unit of poly chloroethene mark question continues on the next page turn over wmp jun chem do not write outside the box c the ester diethyl phthalate dep is used in food packaging and in cosmetics c i complete the following equation showing the formation of dep from phthalic anhydride cooch ch cooch ch dep marks c ii deduce the number of peaks in the c n m r spectrum of dep mark c iii one of the peaks in the c n m r spectrum of dep is at ppm table on the data sheet can be used to identify a type of carbon atom responsible for this peak draw a circle around one carbon atom of this type in the structure below cooch ch cooch ch d the mass spectrum of dep includes major peaks at m z the molecular ion and at m z write an equation to show the fragmentation of the molecular ion to form the fragment that causes the peak at m z mark marks wmp jun chem do not write outside the box e because of their many uses phthalates have been tested for possible adverse effects to humans and to the environment the european council for plasticisers and intermediates is an organisation that represents the manufacturers of plasticisers the text below is taken from a document written by the organisation research demonstrates that phthalates at current and foreseeable exposure levels do not pose a risk to human health or to the environment experimental evidence shows that phthalates are readily biodegradable and do not persist for long in the environment e i hydrolysis of dep in an excess of water was found to follow first order kinetics write a rate equation for this hydrolysis reaction using dep to represent the ester mark e ii suggest what needs to be done so that the public could feel confident that the research quoted above is reliable marks extra space turn over wmp jun chem
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Question 5 / 5

AQA Jun 2013 Paper 4 Q5 do not write outside the box lactic acid ch ch oh cooh is formed in the human body during metabolism and exercise this acid is also formed by the fermentation of carbohydrates such as sucrose c h o a i give the iupac name for lactic acid mark a ii write an equation for the formation of lactic acid from sucrose and water mark b a molecule of lactic acid contains an asymmetric carbon atom the lactic acid in the body occurs as a single enantiomer a racemic mixture racemate of lactic acid can be formed in the following two stage synthesis ch c o stage hcn ch c cn oh stage ch c cooh oh b i name and outline a mechanism for stage name of mechanism mechanism marks wmp jun chem do not write outside the box b ii give the meaning of the term racemic mixture racemate mark b iii explain how you could distinguish between a racemic mixture racemate of lactic acid and one of the enantiomers of lactic acid marks c a mixture of lactic acid and its salt sodium lactate is used as an acidity regulator in some foods an acidity regulator makes sure that there is little variation in the ph of food c i write an equation for the reaction of lactic acid with sodium hydroxide mark c ii the acid dissociation constant ka for lactic acid has the value mol dm at k calculate the ph of an equimolar solution of lactic acid and sodium lactate marks question continues on the next page turn over wmp jun chem do not write outside the box c iii suggest an alternative name for the term acidity regulator explain how a mixture of lactic acid and sodium lactate can act as a regulator when natural processes increase the acidity in some foods name explanation marks extra space d the cup shown is made from pla poly lactic acid pla is the condensation polymer formed from lactic acid the polymer is described as biodegradable and compostable compostable material breaks down slowly in contact with the moist air in a garden bin this produces compost that can be used to improve soil the manufacturers stress that pla cups differ from traditional plastic cups that are neither biodegradable nor compostable d i draw a section of pla that shows two repeating units marks wmp jun chem do not write outside the box d ii name the type of condensation polymer in pla mark d iii an intermediate in the production of pla is a cyclic compound c h o that is formed from two pla molecules draw the structure of this cyclic compound d iv traditional non biodegradable plastic cups can be made from poly phenylethene commonly known as polystyrene draw the repeating unit of poly phenylethene mark mark d v the manufacturers of pla claim that the material will break down to compost in just weeks suggest one reason why pla in landfill may take longer than weeks to break down mark turn over wmp jun chem
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