1 Group 2

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Oxford Textbook Pages : 108 - 111

CGP Revision Guide Pages : 60, 62

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Show Specification Ref : 3.1.2a, 3.1.2b, 3.1.2c, 3.1.2d, 3.1.2e, 3.1.2f

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Question 1 / 5

January 2010 QP – Unit 2 AQA Chemistry A-level_question_4 areas outside the box will not be scanned for marking group metals and their compounds are used commercially in a variety of processes and applications a state a use of magnesium hydroxide in medicine mark b calcium carbonate is an insoluble solid that can be used in a reaction to lower the acidity of the water in a lake explain why the rate of this reaction decreases when the temperature of the water in the lake falls marks extra space c strontium metal is used in the manufacture of alloys c i explain why strontium has a higher melting point than barium marks extra space wmp jan chem c ii write an equation for the reaction of strontium with water areas outside the box will not be scanned for marking mark d magnesium can be used in the extraction of titanium d i write an equation for the reaction of magnesium with titanium iv chloride mark d ii the excess of magnesium used in this extraction can be removed by reacting it with dilute sulfuric acid to form magnesium sulfate use your knowledge of group sulfates to explain why the magnesium sulfate formed is easy to separate from the titanium mark turn over for the next question turn over wmp jan chem
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Question 2 / 5

June 2011 QP – Unit 2 AQA Chemistry A-level_question_9 do not write outside the box a organic reaction mechanisms help chemists to understand how the reactions of organic compounds occur the following conversions illustrate a number of different types of reaction mechanism when bromopentane reacts with ethanolic koh two structurally isomeric alkenes are formed a i name and outline a mechanism for the conversion of bromopentane into pent ene as shown below ch ch ch chbrch ch ch ch chch ethanolic koh a ii draw the structure of the other structurally isomeric alkene produced when bromopentane reacts with ethanolic koh marks mark question continues on the next page turn over wmp jun chem do not write outside the box b name and outline a mechanism for the following conversion ch ch c ch br ch ch c ch br br marks wmp jun chem do not write outside the box c name and outline a mechanism for the following conversion ch ch ch br ch ch ch nh nh marks end of questions wmp jun chem
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Question 3 / 5

June 2013 QP – Unit 2 AQA Chemistry A-level_question_11 do not write outside the box a group metals and their compounds are used commercially in a variety of processes strontium is extracted from strontium oxide sro by heating a mixture of powdered strontium oxide and powdered aluminium consider these standard enthalpies of formation hf kj mol sro s al o s sro s al s sr s al o s use these data and the equation to calculate the standard enthalpy change for this extraction of strontium the use of powdered strontium oxide and powdered aluminium increases the surface area of the reactants suggest one reason why this increases the reaction rate suggest one major reason why this method of extracting strontium is expensive marks question continues on the next page turn over wmp jun chem b explain why calcium has a higher melting point than strontium do not write outside the box marks c magnesium is used in fireworks it reacts rapidly with oxygen burning with a bright white light magnesium reacts slowly with cold water write an equation for the reaction of magnesium with oxygen write an equation for the reaction of magnesium with cold water give a medical use for the magnesium compound formed in the reaction of magnesium with cold water marks end of questions copyright aqa and its licensors all rights reserved wmp jun chem
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Question 4 / 5

June 2012 QP – Unit 4 AQA Chemistry A-level_question_4 do not write outside the box a acyl chlorides and acid anhydrides are important compounds in organic synthesis outline a mechanism for the reaction of ch ch cocl with ch oh and name the organic product formed mechanism name of organic product marks b a polyester was produced by reacting a diol with a diacyl chloride the repeating unit of the polymer is shown below o c ch ch c o ch ch ch ch ch b i name the diol used mark b ii draw the displayed formula of the diacyl chloride used mark wmp jun chem do not write outside the box b iii a shirt was made from this polyester a student wearing the shirt accidentally splashed aqueous sodium hydroxide on a sleeve holes later appeared in the sleeve where the sodium hydroxide had been name the type of reaction that occurred between the polyester and the aqueous sodium hydroxide explain why the aqueous sodium hydroxide reacted with the polyester type of reaction explanation marks c i complete the following equation for the preparation of aspirin using ethanoic anhydride by writing the structural formula of the missing product cooh oh h c h c cooh aspirin ch mark c ii suggest a name for the mechanism for the reaction in part c i mark c iii give two industrial advantages other than cost of using ethanoic anhydride rather than ethanoyl chloride in the production of aspirin advantage advantage marks question continues on the next page turn over wmp jun chem do not write outside the box d complete the following equation for the reaction of one molecule of benzene dicarboxylic anhydride phthalic anhydride with one molecule of methanol by drawing the structural formula of the single product ch oh e the indicator phenolphthalein is synthesised by reacting phthalic anhydride with phenol as shown in the following equation mark oh conc h so heat oh c oh h o phenol phenolphthalein e i name the functional group ringed in the structure of phenolphthalein mark e ii deduce the number of peaks in the c n m r spectrum of phenolphthalein mark e iii one of the carbon atoms in the structure of phenolphthalein shown above is labelled with an asterisk use table on the data sheet to suggest a range of values for the peak due to this carbon atom in the c n m r spectrum of phenolphthalein mark wmp jun chem do not write outside the box f phenolphthalein can be used as an indicator in some acid alkali titrations the ph range for phenolphthalein is f i for each acid alkali combination in the table below put a tick in the box if phenolphthalein could be used as an indicator acid alkali tick box sulfuric acid sodium hydroxide hydrochloric acid ammonia ethanoic acid potassium hydroxide nitric acid methylamine f ii in a titration nitric acid is added from a burette to a solution of sodium hydroxide containing a few drops of phenolphthalein indicator give the colour change at the end point mark marks turn over for the next question turn over wmp jun chem
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Question 5 / 5

June 2013 QP – Unit 4 AQA Chemistry A-level_question_5 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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