Spec reference

Mark Scheme

CS 6.5.1.1 6.5.1.2

Triple

4.5.1.1 4.5.1.2

CS

6.5.1.3

Triple 4.5.1.3

CS

6.5.1.4

Triple 4.5.1.4

Bigger than Equal to

CS 6.5.1.4

Triple

4.5.1.4 (HT only)

CS

6.5.2

Triple 4.5.2

CS 6.5.3

Triple

4.5.3

CS

6.5.6.1.1 6.5.6.1.2 6.5.6.1.3

Triple

4.5.6.1.1 4.5.6.1.2 4.5.6.1.3

CS

6.5.6.1.5

Triple 4.5.6.1.5

CS 6.5.6.2.1

Triple 4.5.6.2.1

CS

6.5.6.2.2

Triple 4.5.6.2.2

CS

6.5.6.2.3

Triple 4.5.6.2.3

CS

6.5.6.3.1 6.5.6.3.2 6.5.6.3.3 6.5.6.3.4

Triple 4.5.6.3.1 4.5.6.3.2 4.5.6.3.3

4.5.6.3.4

HT only CS

6.5.7.1 6.5.7.2

Triple 4.5.7.1

4.5.7.2

4.8.1.1

4.8.1.2

4.8.1.3

4.8.2

Electricity

CS 6.2.1.3

Triple

4.2.1.3 • Use of equation I = Q/t or V = IR

or • 72/120 = 0.6A or 1.5/0.6

• 2.5Ω

CS 6.2.1.3

Triple

4.2.1.3

CS

6.2.1.4

Triple 4.2.1.4

CS 6.2.1.4

Triple

4.2.1.4

CS

6.2.2

Triple 4.2.2

CS 6.2.3

Triple 4.2.3

CS

6.2.4.1 6.2.4.2

Triple 4.2.4.1 4.2.4.2

CS

6.2.4.3

Triple 4.2.4.3

Waves

4.6.1.1

4.6.1.2

4.6.1.3 1 degree

4.6.1.5

4.6.2.1

4.6.3.1 4.6.3.2

Energy

4.1.1.1

4.1.1.3

4.1.1.4

4.1.2.1

4.1.2.2

0 or 0%

4.1.3

CS 6.3.1.1 6.3.1.2 Triple

4.3.1.1 4.3.1.2

CS 6.3.1.1 Triple

4.3.1.1

4.4.2.1 4.4.2.2

4.4.3.1 4.4.3.2 4.4.3.3

4.4.4.1

4.4.4.2

Spec ref

CELLS AND SYSTEMS: prove it mark schemes

4.1.1.2

4.1.1.4

4.1.1.5

4.1.1.6

5 a Split into two / binary fission

b = 1.5 (1)

1.5 × 24 = 36 divisions in 24 hours (1) Number of bacteria at end of growth period = 1 x 236 = 68719476736 (1) c (HT only) = 6.87 × 1010 (1)

4.1.1.6

4.1.3.1

4.1.3.2

4.1.3.2 (RP3)

4.1.3.3

4.2.1

4.2.2.2

4.2.2.2

4.2.2.3

4.2.3.1

4.2.3.2

4.2.3.2

4.4.1.1

4.4.1.2

4.4.1.2

4.4.1.2

4.4.1.3

4.4.2.1

4.4.2.2

4.4.2.3

4.5.1

4.5.2.1

4.5.2.1

4.5.2.2

4.5.2.3

4.5.2.4

4.5.3.1

4.5.3.2

4.5.3.3.

4.5.3.4

4.5.3.6

4.5.3.7

4.5.4.1

4.5.4.2

Spec ref

GENETICS AND EVOLUTION: prove it mark schemes

4.1.2.1

4.1.2.2

4.1.2.3

4.2.2.7

4.6.1.1

4.6.1.2

4.6.1.3

4.6.1.4

4.6.1.5

4.6.1.5

4.6.1.6

4.6.1.7

4.6.1.8

4.6.2.1

4.6.2.2

4.6.2.3

4.6.2.4

4.6.2.4

4.6.3.1

4.6.3.2

4.6.3.3

4.6.3.5

4.6.3.7

4.6.4

INTERDEPENDENCE: Prove it mark schemes 4.7.1.1

4.7.1.2 4.7.1.3

4.7.1.4

4.7.2.1

4.7.2.1 (r.p 9)

1. 9.75 (11 + 8 + 11 + 9)/4 2. 3. 11

4.7.2.2

4.7.2.3

4.7.2.3 (r.p 10)

1. Independent variable – Temperature (ºC); dependent variable – time taken to digest lactose (minutes) 2.

3. 40 degrees 4. Repeat the experiment using smaller intervals between 35 and 45 degrees. 5. Plot a line graph with temperature (in °c) on the x-axis and time taken to digest lactose (in minutes) on the y-axis. Plot each point using a cross. Draw a curve of best fit through the points.

4.7.2.4

4.7.3.1

4.7.3.2

4.7.3.3

4.7.3.4

4.7.3.5

4.7.3.6

4.7.4.1

4.7.4.2

4.7.4.3

4.7.5.1

4.7.5.2

4.7.5.3

4.7.5.4

4.7.5.4

Spec. ref

MIRCOBES AND HEALTH: prove it mark schemes

4.2.2.1

4.2.2.4

4.2.2.5 4.2.2.6

4.2.2.7

4.3.1.2 4.3.1.3

4.3.1.4 4.3.1.5

4.3.1.6

4.3.1.7

4.3.1.8

4.3.1.9

4.3.2.1 4.3.2.2

4.3.3.1

4.3.3.2

Prove it mark schemes Chemistry 5.1.1.1 3

5.1.1.2

5.1.1.3

5.2.1.1 5.2.1.2

5.2.1.5

5.2.2.1 5.2.2.2

5.2.2.3

5.2.2.4

5.2.2.5

5.2.2.7 5.2.2.8

5.2.3.1 5.2.3.2

5.2.3.3

5.7.1.1

5.7.1.2

5.7.1.3

5.7.1.4

5.8.1.1 5.8.1.2

5.3.1.1 5.3.1.2

5.3.2.1

NOTE: Question gives Mr of C as 14 not 12!

5.3.2.2

Spec Ref.

Mark scheme

CS

5.1.4.3

5.4.1.4 (HT)

Triple

4.4.1.3

4.4.1.4

(HT)

carbon is above lead in the reactivity series } NOT

for 1 mark

carbon is below aluminium in the reactivity series } OXIDE

for 1 mark

carbon can remove oxygen from/reduce lead oxide or cannot remove oxygen from aluminium oxide not aluminium more reactive than lead

for 1 mark

OR similar ideas in comparing bond strengths

3

CS

5.4.2.5

Triple

4.4.2.4

Red (accept orange)

Neutralisation H+ + OH- H2O

CS

5.4.2.5 (HT)

Triple

4.4.2.6(HT)

C A D B

1

acidic

1

CS

5.4.3.1

5.4.3.2

Triple

4.4.3.1

4.4.3.2

CS

5.4.3.3

5.4.3.5 (HT)

Triple

4.4.3.3

4.4.3.5

0 marks

No relevant content.

Level 1 (1–2 marks)

A brief reason is given against extraction or for recycling. There is little scientific terminology used.

Level 2 (3–4 marks)

Some reasons are given with clear statements against extraction and or for recycling. Some scientific terminology is used

(HT) Level 3 (5–6 marks)

Several reasons are given with a detailed explanation against extraction and for recycling. Scientific terminology is used accurately

examples of chemistry points made in the response

ignore uses and properties of aluminium. Comparative statements count for both methods

extraction:

• limited resources of aluminium oxide

• higher temperatures required allow quoted temperatures eg extracted at 950°C

• large amount of energy required

• expensive

• requires mining / quarrying

• process takes longer / has more stages

• produces more carbon dioxide / greenhouse gases

recycling:

• saves resources

• cheaper to recycle

• uses less energy

• only needs to be melted allow quoted temperatures eg melted / recycled at 700°C

• less electricity needs to be used

• less effect on environment

• example of effect on environment eg less destruction of habitats

• avoids need for disposal / use of landfill

• no need for quarrying

• sustainable

[6]

CS

5.4.3.4

5.4.3.5 (HT)

Triple

4.4.3.4

4.4.3.5 (HT)

CS

5.9.1.1

5.9.1.2

Triple

4.9.1.1

4.9.1.2

any three described from:

• plants take in (CO2), accept photosynthesis uses (do not accept CO )

• converted to glucose / starch / carbohydrates

ignore carbon compounds by itself

• CO2 locked up in fossil fuels, accept coal / oil / natural gas / methane for fossil fuels

• CO2 reacts with / dissolves (sea)water, accept ocean removes CO2

• producing hydrogencarbonates, accept carbonic acid

• producing carbonates, accept named carbonates

• marine animals use carbonates to make shells, do not accept bones

• forms sedimentary rocks, accept limestone / chalk/marble, do not accept sediments alone

CS

5.9.1.3

5.9.1.4

Triple

Main changes

• oxygen increased because plants / algae developed and used carbon dioxide for photosynthesis / growth producing oxygen; carbon dioxide decreased because of this

• carbon dioxide decreased because oceans formed and dissolved / absorbed carbon dioxide; carbon dioxide became locked up in sedimentary / carbonate rocks and / or fossil fuels

4.9.1.3

4.9.1.4

• oceans formed because the Earth / water vapour cooled and water vapour in the atmosphere condensed

• continents formed because the Earth cooled forming a supercontinent / Pangaea which formed the separate continents

• volcanoes reduced because the Earth cooled forming a crust.

Other changes

• nitrogen has formed because ammonia in the Earth’s early atmosphere reacted with oxygen / denitrifying bacteria.

6

CS

5.9.2.1

5.9.2.2

Triple

4.9.2.1

4.9.2.2

general increase in temperature caused by increase in greenhouse gases

1

any two human activities correctly linked to a named greenhouse gas

e.g.

increased burning of fossil fuels causes more carbon dioxide

deforestation causes more carbon dioxide

more cattle production causes more methane

use of landfill causes more methane

2

CS

5.9.3.1

5.9.3.2

Triple

4.9.3.1

4.9.3.2

CS

5.10.1.2

5.10.1.3

water needs more / different processes

1

because it contains any two from:

• more organic matter

• more microbes

Triple

4.10.1.2

4.10.1.3

• toxic chemicals or detergents

2

CS

5.10.1.4(HT)

Triple

4.10.1.4

(HT)

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

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

6

CS

5.10.2.1

Triple

4.10.2.1

CS

5.10.2.2

Triple

4.10.2.2

(recycling) is used to conserve iron (ore) or energy or resources or minimise pollution or reduce the need to quarry

allow reverse arguments.

1

(not reuse) because of damage, paint removal, rusting/corrosion, metal fatigue/weaker

1

(not landfill) because sites have limited space or loss of habitats

allow to reduce the use of landfill

1

CS

5.5.1.2

Triple

4.5.1.2

A

1

C

1

CS

5.5.1.3

(HT)

Triple

4.5.1.3

(HT)

products are at a lower energy level than reactants

if candidate has drawn a profile for an endothermic reaction penalise first marking point only

activation energy correctly drawn and labelled

1

ΔH correctly labelled

1

–93 (kJ per mole)

correct answer with or without working gains 3 marks

allow 2 marks for +93 kJ per mole

if any other answer is seen award up to 2 marks for any two of the steps below:

bonds broken (614 + 193) = 807 (kJ) or (614 + 193 + (4 × 413)) = 2459(kJ)

bonds formed (348 + 276 + 276) = 900(kJ) or 348 + (2 × 276) + (4 × 413) = 2552(kJ)

bonds broken – bonds formed

allow ecf for arithmetical errors

3

more energy is released when the bonds (in the products) are formed

1

than is needed to break the bonds (in the reactants)

1

if no other marks gained, allow 1 mark for energy released for bond making and energy used for bond breaking

Spec Ref.

Mark scheme

CS

5.6.1.1

5.6.1.2

Triple

4.6.1.1

4.6.1.2

CS

5.6.1.2

Triple

4.6.1.2

any two from:

• temperature (of the HCl) • mass or length of the magnesium • surface area of the magnesium • volume of HCl

(i) (a greater concentration has) more particles per unit volume

allow particles are closer together 1

therefore more collisions per unit time or more frequent collisions. 1

(ii) particles move faster allow particles have more (kinetic) energy 1

therefore more collisions per unit time or more frequent collisions 1

collisions more energetic (therefore more collisions have energy greater than the activation energy) or more productive collisions

1

CS

5.6.2.1

5.6.2.2

5.6.2.3

Triple

4.6.2.1

4.6.2.2

4.6.2.3

CS

5.6.2.6 (HT)

5.6.2.7

(HT)

Triple

4.6.2.6

(HT)

4.6.2.7

(HT)

0 marks No relevant content

Level 1 (1−2 marks) At least one statement about the effect of a condition on either rate or yield.

Level 2 (3−4 marks) Correct statements about the effect of at least one condition on rate and yield.

Level 3 (5−6 marks) Correct statements about the effect of at least one condition on rate and yield and at least one correct statement about compromise conditions.

Examples of the points made in the response

Temperature

• a higher temperature gives a lower yield

• a higher temperature gives a faster rate

Pressure

• a higher pressure gives a higher yield

• increase in yield gets less as pressure increases

• a higher pressure gives a faster rate

• increase in rate increases as pressure increases

Catalyst

• using a catalyst speeds up reaction

• catalysts allow a lower temperature to be used and so save energy / reduce

energy costs

Compromise

• a higher pressure gives a greater yield but increases costs / (safety) risks

• a high pressure gives a faster rate but increases costs / risks

• a high temperature makes reaction faster but reduces yield

• a catalyst makes reaction faster so a lower temperature can be used which will increase the yield

6

Graph drawing – prove it mark scheme Bar chart

Line graph

Pie chart