Web view• hard. do . not . accept flexible ... mark unless they say add water to the calcium...

M1.         (a)     causes dust pollution1

increases traffic1

(b)     (i)      decomposition1

(ii)                44(g)1

(c)     (calcium) hydroxide1

(calcium) carbonate1

substances must be in the order shown[6]

M2.          (a)     calcium oxide1

calcium hydroxide1

calcium carbonate1

substances must be in the order shown

(b)     (i)      strength of mortar decreases (as volume of sand increases)1

(ii)     400 (cm3)1

because the height_ the metal ball dropped from shouldbe 42 cm and not 37 cm

accept because the other results show that the height_ the metal ball dropped from should have an interval of 6cm

1

(c)     contains aggregateallow bonding is stronger

1[7]

M3.          (a)     (i)      copper1

(ii)                50p1

(iii)               25 (%)1

(b)     any two from:

•        high value of copperallow copper is expensive or contains other metals (that may have higher value now)

•        less copper available or copper ores exhausted /only low-grade ores available

allow copper is non-renewable

•        high demand for copper

•        inflation of prices2

[5]

M4.          (a)     (i)      because large amounts of energy would be needed toextract the copper

accept because it is labour-intensive to extract copper from this landaccept because copper would have to be extracted from a large area of land (owtte)

1

(ii)     any one from:

•        produces large amounts of solid waste

•        atmospheric pollution from carbon dioxide / sulfur dioxide

•        more lorries / traffic1

(b)     (i)      iron is cheapaccept iron is much more abundant than copper

1

(ii)     iron displaces copper from solutions of its saltsaccept iron is more reactive than copper

1

(c)     (i)      any two from:

•        less expensive / energy to extract the small amountsof copper

•        plants will remove carbon dioxide from the atmosphereas they grow

•        can release energy when plants are burned2

(ii)     not continuous as it takes a long time for plants to growaccept supply not continuous as plants only harvested once / twice a year

1[7]

M5.          (a)     any two points one mark eachaccept comparison between aluminium and iron

aluminium has:

•        a low densityaccept lighter or fewer pylons

•        a good conductor of electricity

•        does not corrode or rustdo not accept does not react with airdo not accept last longer

2

OR

•        iron has:

•        high density

•        is a less good conductor (of electricity)

•        rusts or reacts with air

(b)     any 5 from:

•        employment of people or cost of employment

•        depletion or use of resourcesdo not accept depletion here

•        cost of energy resources

•        cost of machines or buildings

•        pollution by noise from traffic or quarrying

•        air pollution by dust or traffic fumes

•        danger of traffic on roads

•        damage to landscape (eyesore)

•        damage to habitats of wildlife

•        lowers the value of houses nearby

•        subsidence or vibration can affect roads or houses

•        providing raw materialsdo not accept danger or falling in

5[7]

M6.          (a)     calcium carbonatenot formula

1

(b)     calcium carbonate → calcium oxidenot common namesallow correct formulae

1

+ carbon dioxide1

(c)     calcium hydroxidenot formula

1

(d)     CaO + H2O → Ca(OH)2

allow if doubled

all formulae correct, no extra ones1

balanced1

(e)     filtrationallow centrifugation

not decantingnot evaporation, crystallisation

1

(f)      electrolysis stated or implied

          molten MgO / magnesium oxide is ionic / Mg2+ goes to cathodenot just heated

1

or add sodium / K / Ca / Li / a more reactive metal1

displaces Mg / reduces Mggive no marks if reference made to reduction by C or H

1[9]

M7.         (i)      a reaction in which the products canbe changed back to reactants

accept a reaction that can go forwards or backwards

1

under certain conditions1

(ii)      Mr CaCO3  =  1001

Mr CaO  =  561

mass of CaO  =  140 (tonnes)1

mark consequentially[5]

M8.          (a)     limestoneclay

both for 1 mark1

(b)     watersandcrushed rock

for 1 mark each1

[4]

M9.          (a)     (i)      clayfor one mark

(ii)     calcium oxide / quicklime / CaOfor one mark

(iii)     sensible answers such as cost of fuel etc. / accept a wide range

of appropriate answersfor one mark

3

(b)     sandgravel (owtte) e.g. crushed rockwater

any two for 1 mark each2

[5]

M10.          (a)     unreactive / near bottom of reactivity series1

(b)     carbon more reactive / higher up reactivity series1

(c)     very reactive / near top of reactivity series1

          cannot use displacement methods / can only be extracted by electrolysis / hadto wait discovery of electricity

1[4]

M11.          (i)      zincaccept Zn

1

          iron onlyaccept Fe

1

          copperaccept Cudo not credit iron

1

(ii)      iron1

(iii)     copper or iron or manganeseaccept Cu or Fe or Mn

1[5]

M12.          (a)     This part was not marked1

(b)     electrolysis1

          because calcium is more reactive (than aluminium or carbon)accept it is more reactiveor very reactive

1

OR

in a blast furnace1

          because calcium is less reactive (than carbon or lower)1

(c)     any equation from1 mark for correct formulae1 mark for balancing

2ZnO  +  C  →  2Zn  +  CO2

ZnO  +  CO  →  Zn  +  CO2

ZnO  +  C  →  Zn  +  CO1

[5]

##

          from limestone/marble;from calcium carbonate;action of heat/thermal decomposition;(other product is) carbon dioxide

any three for 1 mark each[3]

-

M14.          (a)     (i)      limestone / chalk / marble1

(ii)     breakdown / splits up1

with heat1

(iii)     to burn / react with air / oxygen1

         release energy / heat / exothermic / keeps temperature high1

(iv)    calcium carbonate → calcium oxide + carbon dioxide

calcium oxide1

correct equation1

(b)     (i)      exothermic / slaking / hydration not hydrolysis

1

(ii)     calcium hydroxide / slaked line1

         mortar / neutralise acidity in soil / neutralise acid lake water / softenhard water / to make cement

not in agriculturenot to make lime water

1[10]

M15.          (a)     calciumcarbonoxygen

2 correct for 1 mark3 correct for 2 marks

2

(b)     cementglass

each for 1 mark2

(c)     (i)      allows coal to bum / flushes out CO2

for 1 mark1

(ii)     produced by burning coalproduced by decomposition of limestone

each for 1 mark2

(d)     (i)      calcium oxide + water → calcium hydroxideor quicklime + water → slaked lime

for 1 mark(allow composite equation from these two)

1

(ii)     to neutralise it / because it is alkaline or basicfor 1 mark

1[9]

M16.          (i)      (hot air) gives faster reaction makes coal burn faster(provides air / oxygen to help to) allow the coal to burn / helps combustionflushes out the waste / gases / carbon dioxide

any one for 1 mark1

(ii)      decomposition of limestone yields carbon dioxide (owtte)the combustion / burning of coal produces carbon dioxide (owtte)

each for 1 mark2

[3]

M17.          (a)     good (electrical) conductorallow low reactivity / resistance to corrosiondo not accept heat conductor

1

(b)     a mixture of metalsaccept contains more than one type of metal

1

(c)     (i)      any one from:

•        eyesore

•        destruction of habitats

•        pollution of water

•        dust pollution

•        noise

•        traffic pollution1

(ii)     acid rainallow sulfur dioxide is a pollutant

1

(d)     (i)      running out of copper (ores)1

(ii)     any two from:

•        any specific example of using less copper

•        reuse / recycleallow do not throw copper / brass away

•        use low-grade copper ores

•        use other metals / materials in place of copper2

[7]

M18.          (a)     any three from:

•        resources / aluminium / ores are conservedaccept converse argument

•        less / no mining or less associated environmental problemseg quarrying / eyesore / dust / traffic / noise / loss of land / habitat

ignore just pollution

•        less / no waste (rock) / landfilldo not accept ‘wastes 50% of the ore’

•        no purification / separation (of aluminium oxide)

•        (aluminium extraction / production) has high energy / electricity / heat / temperature requirements

•        less carbon dioxide produced

accept no carbon dioxide producedignore references to cost

3

(b)     statementignore density

1

          linked reasoneg(pure) Al / it is weak / soft (1)as layers / rows can slide (over each other) (1)oralloy / other metals / they make it stronger / harder (1)stops layers / rows sliding over each other (1)accept disrupts the structure owtte if no other mark awardedaccept to form an alloy or to change properties for 1 mark

1[5]

M19.          (a)     (an alloy) that can return to its original shape (after being deformed / bent / twisted)

accept (on heating / cooling) it returns to its shape

1

(b)     any two from:

•        brass / it is a mixtureaccept brass / it is not pure

•        zinc changes structure / disrupts patterns or layers

•        copper metal atoms / layers able to slide over each otheraccept zinc prevents atoms / layers sliding over each other

2

(c)     (i)      oxygen / O2 / O1

(ii)     lead remains (in furnace) because of its high boiling point1

         zinc boils / evaporates (out of furnace) because of its low boiling point 1 if neither mark awarded then allow 1 mark for different boiling points

ignore references to melting points1

[6]

M20.          (a)     (i)      calcium oxide / CaO1

         carbon dioxide / CO2

products can be in either orderignore chemical names other than calcium oxide or carbon dioxide

1

(ii)     (thermal) decompositionaccept endothermic

1

(b)     (i)      (chemical) reaction / reactaccept calcium hydroxide / slaked lime producedignore incorrect products

1

         energy / heat released / exothermicignore gets hot / heats upif neither mark awarded then allow ‘mixing the chemicals heats up the coffee’ for 1 mark

1

(ii)     any two from:

•        foil has been broken(*)

•        ring pull used(*)(*)if neither mark awarded accept ‘cannot / difficult to repair’ for 1 markignore button pushed

•        quicklime and / or water mixed / reactedaccept reaction not reversibleaccept cannot / difficult to replace quicklime / water / chemicals

2[7]

M21.          (a)     tungsten1

          has the high(est) melting pointaccept that metals other than tungstenare likely to melt

1

(b)     argon1

          is an unreactive gasaccept that gases other than argon are reactiveaccept that argon is a noble gas or in Group 0

1[4]

M22.          (a)     1 / one1

          3 / three1

(b)     (i)      (wear safety) glasses / masks / glovesaccept do not handle hot objects / usetongs or accept other safety pointssuch as, ‘tie hair back’

1

(ii)     calcium oxideaccept quicklime

1

(iii)     carbon dioxide / CO2 is given offaccept a gas is given off

1

(d)     (i)      any two from:

•        dust / atmospheric pollution

•        noise

•        eyesore

•        destroys habitats

•        (extra) traffic

•        any other named pollution or description of pollution2

(ii)     any one from:

•        employment

•        increases local trade / makes money

•        future development of quarry recreation / park / lake / reservoir       do not accept cheaper houses / land /       new roads

1[8]

M23.          (a)     (i)      contain enough metal to make it economical / worth while to extract

1

(ii)     reductionaccept displacementaccept redox

1

(iii)     Fe + CO2

do not accept Fe2 / Fe4

1

correct balancingaccept multiples and halves

2Fe2O3 + 3C → 4Fe + 3CO2

allow Fe2 / Fe4 as ecf1

(b)     Pure Iron

          (in pure metal all the atoms are the same size and) able to slip / slide over eachother – (property soft)

OWTTEignore references to molecules / particlesif they say ‘move’ both times, allow one mark but ‘crack’ or ‘split’ is wrong..

1

Cast iron

          (in cast iron) different sized atoms / larger atoms or structure is distorted / disrupted

OWTTE1

          so it is difficult for layers of atoms to slip / slide over each otherOWTTE

1

(c)     any three from:

•        conserves / saves resources / metal ores

•        saves energy resources (used for extraction / processing)accept cheaper / saves money

•        decreases waste materials

•        decreases a named pollutiondo not accept acid rain

3[10]

M24.          (a)     (i)      any one from:

•        iron ore is a limited resource / non-renewable

•        iron is in high demand

•        provide jobs

•        economic advantage1

(ii)     any two from:

•        would damage (wildlife) habitats / countryside / greenfield sites

•        extra traffic

•        visual (pollution) / eyesore

•        noise (pollution) / sound (pollution)

•        dust (pollution)

•        river (pollution)

•        carbon dioxide (from traffic) / adds to greenhouse effect / globalwarming

•        damage roads / buildings by vibrations / shockwaves2

(b)     (i)      carbon monoxide / carbonaccept formulae CO / C

1

(ii)     atomsaccept (particles) are all the same (size) / type for one mark

1

are all the same (size) / type1

(iii)     any two from:

•        impurities / carbon / different (sized) atoms or elements or metals

•        changes the structure / disrupts the pattern or layers

•        prevents layers sliding over each other

•        it is an alloy2

[8]

M25.          (a)     any two from:

•        nitrogenaccept formulae N / N2

•        carbon dioxideaccept formula CO2

ignore CO

•        water (vapour) / steamaccept formula H2O

2

(b)     any three from:no mark for ‘limestone’ or ‘concrete’ on first line – mark advantages only

limestone

•        abundant / localignore ideas of speed of production or easier to use

•        natural material or no ‘processing’ needed

•        relatively easy to cut

•        appearance better

concrete

•        raw materials are abundant

•        can be reinforced (by steel rods) / strong(er) / supported (by steel rods)

accept ‘can build higher’

•        concrete mixture can be poured / moulded / constructed on site

•        less reactive with acid rain / weathering / erosionignore density / extraction / quarrying / pollution / cost

3[5]

M26.          (a)     (i)      Cu2S + 2O2 2CuO + SO2

accept fractions and multiple1

(ii)     any two from:

•        sulfur dioxide       accept sulphur dioxide / sulphur oxide / SO2

•        causes acid rain       ignore other comments eg global warming / ozone / global dimming / greenhouse effect

•        consequence of acid rain eg kills fish / plants2

(b)     any two from:

•        heat (copper oxide with carbon)

•        oxygen is removed by carbonaccept copper (oxide) loses oxygen

orcarbon gains oxygenaccept carbon oxide

or

carbon monoxide / carbon dioxide is produced

or

carbon displaces copperaccept a correct word or balancedsymbol equation

•        because carbon is more reactive than copperallow a correct comparison of reactivity

2

(c)     (i)      electrolysisaccept electroplating

1

(ii)     (electrical) wiring / appliances / coins / pipes / cladding forbuildings / jewellery / making alloys

1

or

named alloys

(d)     any three explanations from:

for recycling

•        less acid rain (pollution)

•        copper reserves last longer / conserved

or

do not run out

•        energy for extraction (saved)

or

less energy required

•        less mining / quarrying

•        less waste (copper) / electrical appliances dumped

or

less landfill

         against recycling

•        collection problems

•        transport problems

•        difficult to separate copper from appliances

•        energy used to melt the collected copperignore electrolysis / pollutionignore ideas about less machinery / plantignore idea of cost

3[10]

M27.          clay1

limestone1

water1

 [3]

M28.          (a)     (i)      5(%)

1

(ii)     0.35

 for 1 mark

2

(b)     (i)      reductionaccept (it’s) reduceddo not accept redox / deoxidation

1

(ii)     heat with / reduce / react with or (chemical) reaction1

         with a metal / element / substance higher in reactivityignore displaceaccept higher named elements or symbolaccept carbon monoxide / coal / cokecorrect word equation for 2 markscorrect formulas for 1 markcorrect balanced symbol equation for 2 marks

1

or

electrolysis:molten                                                                                        (1)electrolysis                                                                                 (1)

[6]

M29.          (a)     (very) small percentage / amount (in the Earth’s crust)

any indication that there is a smallamount, eg not much (left)accept rare (elements) / rareraccept not commonly foundignore cannot find easilyignore hard to extract

1

(b)     (i)      oxygen / O  / O

do not accept O1

(ii)     any one from:

         •        potassium / K•        sodium / Na•        calcium / Ca•        magnesium / Mg

symbols must be correctwrite name and incorrect symbol, ignore symbol

1

(c)     (i)      heating (with) or hot air blown into furnaceaccept high temperatures or (very) hot

1

carbon / carbon monoxide / coke / coking coaldo not accept coal / charcoal accept balanced equation only

or:

         carbon reacts with O  or carbon / coke burning (1)accept balanced equation only CO / CO2

         CO reacts with the ore (1)for naming the reducing agent

1

(ii)     cost of melting ore / electricitymakes aluminium expensive (owtte)or (large amount of) electricity usedor because you have to use electrolysisor aluminium is higher in the reactivity series

or aluminium is harder to reduceor unable to reduce with carbonor the cost of purifying the bauxite

do not accept harder to extract / producemore energy is not enough

1[6]

M30.          (a)     colour1

(b)     Fe2O3 or (Fe3+)2 (O2-)3

2 and 3 should be below halfway on Fe and O

1

(c)     (i)      4  4or correct multiples

1

(ii)     any two from:ignore references to malleable / ductile / conductivity / stiff / boiling point / density

•        high melting pointaccept can withstand high temperatures

•        strong / toughaccept not brittle

•        harddo not accept flexible

•        not (very) reactive2

[5]

M31.          (a)     (i)      heat (the limestone)accept decompose limestoneaccept heat with coke

1

add water / slakedependent on 1st mark unless they say add water to the calcium oxide

1

(ii)     magnesium hydroxide +hydrochloric acid

1

         → magnesium chloride + water / H2O1 mark for each side of the equation(if a symbol equation is given then give 1 mark for correct formulae (all) and 1 mark for balancing)

1[4]

M32.          (a)     Marks awarded for this answer will be determined by the Qualityof Written Communication (QWC) as well as the standard of thescientific response.

No relevant content.0 marks

There is a brief description of the electrolysis of aluminium oxide.Level 1 (1–2 marks)

There is some description of the electrolysis of aluminium oxide.Level 2 (3–4 marks)

There is a clear, balanced and detailed description of theelectrolysis of aluminium oxide.

Level 3 (5–6 marks)

examples of the chemistry points made in the response

•        aluminium oxide is melted / made liquid

•        aluminium ions are attracted to the negative electrode

•        at the negative electrode aluminium is formed oraluminium ions gain electrons

•        oxide ions are attracted to the positive electrode

•        oxygen is formed at the positive electrode or oxideions lose electrons

•        the oxygen reacts with carbon to make carbon dioxide orcarbon dioxide formed at positive electrode.

(b)     there are delocalised electrons / free electrons / electronswhich move within the aluminium / metallic structure

1

therefore these electrons are able to carry the current / charge1

if the candidates use the terms covalent / ionic / molecules / intermolecular incorrectly in the answer this will limit the mark to a maximum of 1.

[8]

M33.          (a)     atoms1

(b)     mixture1

          metal1

          structure1

          smart1

(c)     (i)      any two from:

•        saves raw materials / iron ore

•        saves energy / fuelsaccept cheaper / saves money

•        make new / useful items

•        make money / it is economic

•        reduces pollutionallow less harmful for the environment

•        decreases cost of steel cans

•        reduces carbon dioxide emissions

•        decreases waste materials / use of landfill2

(ii)     any one from:

•        provide information / education of the need to recycle

•        legislate against / charge for waste

•        reward / pay people to recycleaccept fine people for not recycling

•        put labels on the cans

•        provide recycling bags / bins / areas1

[8]

M34.          (a)     (i)      11

         31

(ii)     nucleus1

         electron1

(b)     (i)      methane / CH4

accept natural gasignore airdo not allow other gases

1

(ii)     carbon dioxide1

(c)     (i)      any two from:

•        medical risks

•        asthma

•        cancer

•        dirt

•        causes global warming / global dimming / greenhouse effect / acid rainignore deathaccept effect on healthaccept difficulty breathing/ lung diseaseallow smoke particlesallow harmful for the environment

2

(ii)     any two from:

•        have a test done / scientific evidence

•        independent (evidence)

•        comparison of smoke particles / when differentfuels used

•        medical evidence or more / less asthma attacks orcancer or dirt on cars

2[10]

M35.          (a)     (Chromium =) 201

          in correct order

          (Nickel =) 8accept Chromium = 8 and Nickel = 20 for 1 mark

1

(b)     (i)      (because iron is made up of only) one type of atom1

(ii)     not strongignore soft / corrosive / flexibleaccept it rusts / corrodes or that it could wear awayaccept could change shape / bendaccept layers / atoms could slide (over each other)

1

(iii)     has different sized atoms / particlesorstructure is different/distorted / disrupted

accept not in layers or not regular1

         so it is difficult for layers / atoms / particles to slip / slide (over each other)

accept layers cannot slip / slide1

[6]

M36.          (a)     (i)      oxygen / air reacts with carbon / methane (to form carbon dioxide)

accept from the decomposition / reaction of

calcium carbonateignore CO2 from the air

1

         nitrogen is (unreacted) from the air1

(ii)     CaO1

         CO2

any orderignore wordsany incorrect balancing max 1 mark

1

(b)     any one from:

•        more energy / efficientallow converse for present fuel

•        from a sustainable / renewable resource

•        produces less / no carbon dioxide / greenhouse gases / global warming

ignore no pollution / environmental damage

•        more profit or money for local economyaccept fuel is cheap(er)

•        more readily availableit = different fuel

1

(c)     (i)      any two from:

•        not near where people / residents liveaccept not between cement works and where people liveignore sensors are unsightly

•        not positioned where concentration of particles was likely to be highest

•        not positioned downwind2

(ii)     the average / concentration was 1.8(ppm) or the average / concentrationwas below 2(ppm)

accept 1.8(ppm) is less than 2.0 (ppm)1

(iii)     any three from:

•        children / people suffering asthma attacks

•        result was an average

•        readings (at some (2/3) sensors) could have been higher than 2ppm

•        sensors did not detect particles below 0.5mm

•        small particles / particles below 0.5mm / 0.4mm / 0.3mm / 0.2mm could (still) cause cancer / asthmaignore global dimming or cars becoming dirty or position of sensors

3[11]

M37.          (a)     conducts (electricity) oraccept flexible

          allows electrons / current to flowignore conducts heat

1

(b)     electron1

(c)     (i)      lithium>copper>tungsten or

         Li>Cu>Wall correctallow 1 mark for one metal in the correct position

2

(ii)     has high / highest melting pointaccept has high / highest boiling point

         or

         can withstand the highest temperature1

(d)     unreactive1

[6]

M38.          (a)     (i)      3 / three1

(ii)     5 / five1

(b)     any one from:

•        less / no transportaccept less / no distance

•        less / no (fossil) fuel usedignore references to carbon dioxide / carbon emissions

1

(c)     (i)      carbon dioxide / CO2

for a correct emission1

         (causes) global warming / climate change / greenhouse gasexplanation must be correct for named emissionignore ozone layer

         or

         (cement) particles / smoke (1)

         (causes) asthma / dust / (global) dimming (1)accept breathing problems

         or

         sulfur dioxide / SO2 / nitrogen oxides / NOx (1)

         (causes) acid rain (1)do not accept nitrogen or water vapour for emissionsdo not accept no named emission

1

(ii)     absorb / trap / capture / filter / pass through water / scrub / electrostatic attraction

ignore condense / off setting / different fuel1

[6]

M39.          (a)     (i)      calcium oxide / quicklimeallow calcium monoxidedo not accept calcium dioxideignore chemical formulae

1

(ii)     any three from:

•        carbon dioxide / CO2

•        (carbon dioxide) reacts (with the calcium hydroxide / slakedlime / plaster)

allow reaction 3 identifieddo not allow incorrect reactionignore mixes, unless they state the correct product

•        limestone / calcium carbonate / CaCO3 formsallow marble / chalk

•        water is lost / evaporatesit = plasterallow moistureignore dries

3

(b)     (i)      as the amount / volume of sand decreases the strength of themortar increases

accept as sand decreases the mortar is stronger / harder to crackallow as sand decreases the mortar increasesallow converseignore references to height_ of metal ball

1

(ii)     any two from:

•        400 / 5th result is anomalousaccept two results (36 and 37 / 400 and 500 / 4th and 5th) are almost the sameaccept result at 400 should be 42

•        the interval between the others is similar or the intervalis about 6/7allow the other results fit a pattern / are on a straight line

•        he has only one set of resultsallow he has only done it onceignore reliable

2[7]

M40.          (a)     (i)      reacts with carbon / Caccept burns / oxidises carbon

1

         carbon dioxide / CO2 / gas is formed / given offaccept carbon monoxide / COaccept correctly balanced equation for 2 marksignore state symbols

1

(ii)     change / improve propertiesaccept any specific propertyaccept to make alloys / special steelsignore brittle

1

(b)     any two from:

•        to conserve ores / ironaccept ores / iron are non-renewable / non-sustainableallow less quarrying / mining

•        to prevent the use of landfillsallow reduce waste

•        to conserve energy / fuelaccept fossil fuels are non-renewable

•        to reduce carbon / carbon dioxide emissions

•        to meet EU / International targetsignore costs / demand

2[5]