4 Electronic arrangement

 

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Oxford Textbook Pages : 8 - 9, 14 - 16

CGP Revision Guide Pages : 8 - 9

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Show Specification Ref : 3.1.1.3

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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 2014 Paper 2 Q8 section b answer all questions in the spaces provided do not write outside the box the carboxylic acid methylbutanoic acid is used to make esters for perfumes the following scheme shows some of the reactions in the manufacture of this carboxylic acid ch chch oh ch chch br reaction reaction ch chch cooh ch chch cn methylbutanoic acid reaction a one of the steps in the mechanism for reaction involves the replacement of the functional group by bromine a i use your knowledge of organic reaction mechanisms to complete the mechanism for this step by drawing two curly arrows on the following equation marks br h c ch ch o h h c ch ch br h o ch ch wmp jun chem do not write outside the box a ii deduce the name of the mechanism in question a i give the iupac name of ch chch br marks b reaction is an acid catalysed reaction in which water is used to break chemical bonds when the cn functional group is converted into the cooh functional group infrared spectroscopy can be used to distinguish between the compounds in this reaction deduce the name of the type of reaction that occurs in reaction identify one bond in ch chch cn and a different bond in ch chch cooh that can be used with infrared spectroscopy to distinguish between each compound for each of these bonds give the range of wavenumbers at which the bond absorbs use table a on the data sheet when answering this question marks question continues on the next page turn over wmp jun chem do not write outside the box c when methylbutanoic acid reacts with ethanol in the presence of an acid catalyst an equilibrium is established the organic product is a pleasant smelling ester ch chch cooh ch ch oh ch chch cooch ch h o an ester the carboxylic acid is very expensive and ethanol is inexpensive in the manufacture of this ester the mole ratio of carboxylic acid to ethanol used is to rather than to c i use le chatelier s principle to explain why a to mole ratio is used in your explanation you should not refer to cost marks extra space c ii explain how a catalyst increases the rate of a reaction marks extra space wmp jun chem
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Question 3 / 5

AQA Jun 2016 Paper 4 Q9 b draw the structure of compound s for each of steps and give a reagent and one condition other than heat do not write outside the box marks turn over wmp jun chem do not write outside the box compound r contains carbon and hydrogen by mass the remainder is oxygen the mass spectrum of r contains a molecular ion peak at m z a use these data to show that the molecular formula of r is c h o marks b the infrared spectrum of r c h o is shown in figure figure transmittance wavenumber cm the proton n m r spectrum of r contains five peaks the chemical shift values integration ratios and splitting patterns of these peaks are given in table chemical shift ppm integration ratio table splitting patterns triplet singlet singlet triplet singlet wmp jun chem
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Question 4 / 5

AQA Jun 2011 Paper 5 Q5 do not write outside the box redox reactions occur in the discharge of all electrochemical cells some of these cells are of commercial value the table below shows some redox half equations and standard electrode potentials half equation zn aq e zn s ag o s h aq e o g h aq e f g e ag s h o i h o i f aq e v a in terms of electrons state what happens to a reducing agent in a redox reaction mark b use the table above to identify the strongest reducing agent from the species in the table explain how you deduced your answer strongest reducing agent explanation marks c use data from the table to explain why fluorine reacts with water write an equation for the reaction that occurs explanation equation marks wmp jun chem do not write outside the box d an electrochemical cell can be constructed using a zinc electrode and an electrode in which silver is in contact with silver oxide this cell can be used to power electronic devices d i give the conventional representation for this cell marks d ii calculate the e m f of the cell mark d iii suggest one reason why the cell cannot be electrically recharged mark e the electrode half equations in a lead acid cell are shown in the table below half equation pbo s h aq hso aq e pbso s h o i pbso s h aq e pb s hso aq e v to be calculated e i the pbo pbso electrode is the positive terminal of the cell and the e m f of the cell is v use this information to calculate the missing electrode potential for the half equation shown in the table mark e ii a lead acid cell can be recharged write an equation for the overall reaction that occurs when the cell is being recharged marks question continues on the next page turn over wmp jun chem do not write outside the box f the diagrams below show how the e m f of each of two cells changes with time when each cell is used to provide an electric current lead acid cell cell x e m f v e m f v time hours time hours f i give one reason why the e m f of the lead acid cell changes after several hours mark f ii identify the type of cell that behaves like cell x mark f iii explain why the voltage remains constant in cell x marks extra space wmp jun chem
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Question 5 / 5

AQA Jun 2014 Paper 5 Q1 section a answer all questions in the spaces provided do not write outside the box a write an equation for the process that has an enthalpy change equal to the electron affinity of chlorine mark b in terms of electrostatic forces suggest why the electron affinity of fluorine has a negative value marks c i complete the born haber cycle for silver fluoride by adding the missing species on the dotted lines marks ag g ag g ag g f g ag g ag s agf s wmp jun chem do not write outside the box c ii use the cycle in question c i and the data in table to calculate a value in kj mol for the bond enthalpy of the fluorine fluorine bond table enthalpy change enthalpy of atomisation for silver first ionisation energy for silver electron affinity for fluorine experimental enthalpy of lattice dissociation for silver fluoride enthalpy of formation for silver fluoride marks value kj mol question continues on the next page turn over wmp jun chem do not write outside the box d a theoretical value for enthalpy of lattice dissociation can be calculated using a perfect ionic model the theoretical enthalpy of lattice dissociation for silver fluoride is kj mol d i explain why the theoretical enthalpy of lattice dissociation for silver fluoride is different from the experimental value that can be calculated using a born haber cycle marks extra space d ii the theoretical enthalpy of lattice dissociation for silver chloride is kj mol explain why this value is less than the value for silver fluoride marks extra space wmp jun chem turn over for the next question do not write on this page answer in the spaces provided turn over wmp jun chem
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