Mark schemes. for 1 mark. for 1 mark. An arrow indicating a position between aluminium and zinc. electrolysis

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2 Mark schemes hydrogen for mark oxygen for mark [2] 2 An arrow indicating a position between aluminium and zinc. electrolysis because calcium is more reactive (than aluminium or carbon) accept it is more reactive or very reactive OR in a blast furnace because calcium is less reactive (than carbon or lower) (c) any equation from mark for correct formulae mark for balancing 2ZnO + C 2Zn + CO 2 ZnO + CO Zn + CO 2 ZnO + C Zn + CO [5] 3 (i) hydrogen accept H 2 allow H Page 2 of 2

3 hydroxide accept OH allow OH do not accept lithium hydroxide any two from: it = potassium potassium: accept converse for lithium reacts / dissolves faster allow reacts more vigorously / quickly / violently / explodes ignore reacts more bubbles / fizzes faster allow fizzes more allow more gas moves faster (on the surface) allow moves more melts allow forms a sphere produces (lilac / purple) flame allow catches fire / ignites do not accept other colours 2 [4] 4 because they form hydroxides that give alkaline solutions (in water) the atoms have more electron shells (as move down the group) so the electron in the outer shell is further away from the nucleus which reduces the attraction to the nucleus so the electron is lost more easily from the atom Page 3 of 2

4 (c) electronic structure of lithium drawn correctly electronic structure of oxygen drawn correctly correct charge on ions (Li + and O 2 ) correct number of each ion (2 lithium, oxygen) [0] 5 any three from: concentration of (salt) solution volume of (salt) solution ignore amount of solution initial temperature (of the solution) ignore room temperature surface area / form of metal moles of metal allow mass / amount ignore time ignore size of tube allow ecf (c) (i) four bars of correct height tolerance is + / - half square 3 correct for mark bars labelled 2 one variable is non-continuous / categoric accept qualitative or discrete accept no values between the metals Page 4 of 2

5 (iii) (iv) (v) magnesium because biggest temperature change accept gives out most energy ignore rate of reaction dependent on first mark does not react / silver cannot displace copper because silver not more reactive (than copper) or silver below copper in reactivity series do not accept silver is less reactive than copper sulfate replace the copper sulfate could be implied with any compound of a named metal less reactive than copper allow students to score even if use an insoluble salt [6] 6 gold atom (s) (c) (i) protons any order allow proton neutrons allow neutron 3 / three (d) (i) Al ignore any numbers / charges Page 5 of 2

6 any two from: limited resource expensive in terms of energy / mining effects on the environment, such as, landfill, atmospheric pollution, quarrying allow uses a lot of energy to extract. 2 (e) resistant to corrosion does not react (with water or food) allow one mark for low density with a suitable reason given [0] 7 pure copper is twice as good a conductor as 99% pure copper accept reverse argument accept answers quoting 2 correct values from the graph scores 2 qualitative answer (e.g. pure copper is a better conductor than impure copper) scores or answers quoting a conductivity value from the graph scores 2 Page 6 of 2

7 Marks awarded for this answer will be determined by the Quality of Communication (QC) as well as the standard of the scientific response. 0 marks No relevant content Level ( 2 marks) Simple list of a limited number of points given, with no linking between ideas Level 2 (3 4 marks) A broader set of points made. There will probably not be links between ideas Level 3 (5 6 marks) Answer includes linking between ideas, showing the consequence of either not recycling or the advantage of recycling. Answers such as less fossil fuel needed so less carbon dioxide produced or less carbon dioxide produced so less global warming examples of the points made in the response resources (recycling) conserves supplies of ores copper available for longer as (at present rate of use) copper ores will run out in about 35 years (recycling) conserves supplies of fossil fuels or energy less fuel used at a lower cost land pollution mining scars landscape or produces noise pollution mining destroys wildlife habitats (recycling) less need to mine ores / fossil fuels so less habitat destroyed or less scarring of landscape (recycling) less need to use landfill for waste (c) atmospheric pollution burning fossil fuels produces carbon dioxide / greenhouse gas which (may) cause global warming or climate change extraction produces sulfur dioxide which causes acid rain which can kill trees / fish grow plants then plants are burned accept plants absorb copper (through roots) 6 ash (from burning) contains copper compounds [] Page 7 of 2

8 accept 2O 2 O 2 + 4e 8 (i) aluminium oxide ignore (III) after aluminium (because it provides) heat / energy (to overcome activation energy) (i) contains only one sort of atom the atoms (in cast iron) are different sizes any mention of molecules, maximum mark accept layers are distorted or structure is disrupted which prevents the layers / rows sliding accept an answer in terms of pure iron being softer than cast iron for both marks (c) (i) because aluminium is more reactive than carbon or it = aluminium must be a comparison between the elements because aluminium is above carbon in the reactivity series do not accept any comparison of the reactivity of aluminium and iron reduces / lowers the temperature for the process or lowers the operating temperature or allows ions to move ignore any temperature values allow reduces the (effective) melting point (of Al 2 O 3 ) (iii) 3 accept multiples (iv) electrons are gained (by Al 3+ ) ignore any numbers ignore any reference to oxygen (v) electrodes are made of carbon allow graphite / coke oxygen is produced (at the positive electrode / anode) Page 8 of 2

9 so the electrodes react with the oxygen / are oxidised producing carbon dioxide (gas) accept C + O 2 CO 2 for marking points 3 and 4. [3] 9 (i) calcium oxide in either order carbon dioxide accept correct formulae (iii) C(s) + CO 2 (g) 2CO(g) allow multiples 20 (tonnes) award 3 marks for the correct answer with or without working allow ecf for arithmetical errors if answer incorrect allow up to 2 marks for any of the steps below: / or moles Fe 2 O 3 =.875 ( 0 6 ) or 300 / 60 moles of Fe = 3.75 ( 0 6 ) or 2 moles Fe 2 O 3 mass Fe = moles Fe (tonnes) scores 2 (missing :2 ratio) 420 (tonnes) scores 2 taken M r of iron as 2 3 Page 9 of 2

10 (i) aluminium is more reactive than carbon or carbon is less reactive than aluminium must have a comparison of reactivity of carbon and aluminium accept comparison of position in reactivity series. (iii) (because) aluminium ions are positive ignore aluminium is positive and are attracted / move / go to the negative electrode / cathode where they gain electrons / are reduced / Al e Al accept equation or statements involving the wrong number of electrons. (because) the anodes or (positive) electrodes are made of carbon / graphite oxygen is produced (at anode) which reacts with the electrodes / anodes do not accept any reference to the anodes reacting with oxygen from the air equation C + O 2 CO 2 gains mark (M3) [3] 0 Fe 2 O CO 2Fe + 3 CO 2 correct formulae of reactants correct formulae of products correct balancing (c) iron loses oxygen reduction carbon gains oxygen oxidation any four from: resources for manufacture are limited recycling reduces the use of resources reduces energy consumption in extraction / manufacture reduces waste from processing and extraction reduces environmental impact of extraction 4 Page 0 of 2

11 (d) field lines going through and around coil correct directional arrows (e) any two from: mark for suggestion, mark for correctly linked explanation use many coils or tight coils or long wire () to give a strong magnetic field for lifting heavy objects () explanation must be correctly linked to the suggestion to gain the mark or add an iron core to increase field circuit for lifting or include a switch in circuit so can drop / pick up cars max. 4 [5] Z magnesium sulfate does not react with any of the metals allow there is no change / increase in temperature with any of the metals (c) temperature increase Page of 2

12 (d) Level 2 (3 4 marks): A detailed and coherent plan covering all the steps. The steps include the improvements and are set out in a logical manner. Level ( 2 marks): Simple statements of improvements to the apparatus or steps are made but they may not be set out in a logical manner. 0 marks: No relevant content Indicative content Simple statements stir the solution use the same amount of each solution use the same concentration of solution put insulation or a lid on the beaker measure how high temperature goes (e) Coherent statements in a logical order pour a fixed, measured volume of the metal salt solution into a plastic / polystyrene cup measure and record the temperature of the solution stir and add g of metal to the solution (put a lid on the cup) measure and record the temperature after a set time or measure and record the greatest / highest temperature calculate and record the temperature increase (repeat each individual experiment at least two more times and calculate the mean temperature increase) Activation energy 4 (f) 386 (kj) / % [0] Page 2 of 2