Edexcel GCSE (9–1) Chemistry/Combined Science Test Mark Scheme Question number Answer 1a An explanation linking the following – 1 mark each. 1b Acceptable answers ● The temperature increases as the solid is heated because the particles are gaining energy/moving faster. ● The temperature stays constant while the solid is melting. ● The energy is used to overcome the attractive forces between the particles. ● In the liquid state, the particles can slide over each other. Mark (4) Liquid (1) (Total for Question 1 = 5 marks) Question number Answer Acceptable answers 2a 2.3 (1) 2b 10 (1) 2c A (Period) 2 (1) 2d Mark (2) particle relative relative mass charge electron 1 1837 -1 neutron 1 0/none/ neutral proton 1 (+1) 4 correct: 2 marks 2 or 3 correct: 1 mark 0 or 1 correct: 0 marks © Pearson Education Ltd 2015. Copying permitted for purchasing institution only. This material is not copyright free. 1 GCSE Biology Test Question number Answer 2e Answer should include one idea from each list. Acceptable answers Mark (2) Similarities Both put: ● elements into groups /periods ● elements with similar properties in same group ● metals and non-metals in separately. Differences Mendeleev’s table: ● was arranged by relative atomic mass Allow reverse argument for modern periodic table. ● had gaps ● had fewer elements Allow specific examples e.g. germanium. ● did not include the noble gases. (Total for Question 2 = 7 marks) Question number Answer 3a D a salt and water only (1) 3bi A description including two of the following. (2) 3 b ii 3 b iii Acceptable answers ● (acid) colourless (liquid/solution) Ignore clear. ● (carbonate) green (solid) disappears Allow dissolves. ● effervesces/fizzes/bubbles ● blue/green (solution) (forms) Ignore gas/carbon dioxide given off. A description including the following. ● Dilter (to remove the excess copper carbonate). (1) ● Evaporate some/half of the water (from the filtrate) then leave to cool. (1) (2) Allow leave the water to evaporate slowly. CuCO3 + 2HCl CuCl2 + CO2 + H2O ● Correct reactants (1) ● Correct products (1) Mark (3) Balancing correct formulae (1) (Total for Question 3 = 8 marks) 2 © Pearson Education Ltd 2015. Copying permitted for purchasing institution only. This material is not copyright free. GCSE Biology Test Question number Answer 4a A description including any two from: 4b 4c Acceptable answers (2) ● floats ● moves (around) ● effervescence/fizzing/ bubbles Allow white smoke formed. ● melts/changes to a ball shape Allow dissolve/explodes. ● becomes smaller /disappears. Allow moves (around) on the surface.(2) Ignore gas/hydrogen given off. Ignore burns/catches fire/ ignites/flame/sparks. Ignore addition of indicators. 2Na + 2H2O 2NaOH + H2 ● All 3 balancing numbers correct = 2 marks. ● 1 or 2 correct = 1 mark. Mark Indicative content (2) (6) An explanation including some of the following points. Reactivity series ● Aluminium more reactive than iron/aluminium higher than iron in reactivity series. ● Aluminium forms stronger bonds with oxygen than iron does. ● Aluminium oxide more stable (to decomposition) than iron oxide. ● Aluminium more reactive than carbon/aluminium higher than carbon in reactivity series. Cost ● Electrolysis/electricity (more) expensive (than heating with carbon). ● Heating with carbon is (relatively) cheap method. Iron ● Carbon more reactive than iron/iron less reactive than carbon. ● Iron oxide reduced by heating with carbon. ● No need to use (expensive) electrolysis. Aluminium ● Aluminium oxide difficult to reduce. ● Aluminium oxide cannot be reduced by (heating with) carbon. ● (Cheaper) reduction with carbon does not work. ● Need more powerful method of reduction. ● Therefore must use electrolysis. © Pearson Education Ltd 2015. Copying permitted for purchasing institution only. This material is not copyright free. 3 GCSE Biology Test Question number Answer Acceptable answers Mark No rewardable content = 0 marks Level 1: 1–2 marks ● A limited description e.g. aluminium extracted by electrolysis. ● The answer communicates ideas using simple language and uses limited scientific terminology. ● Spelling, punctuation and grammar are used with limited accuracy. Level 2: 3–4 marks ● A simple description containing two statements referring to one. ● Method of extraction and a cost e.g. iron is extracted by heating. ● Iron oxide with carbon and this is cheaper. ● or The relative reactivity of one metal and a method of extraction e.g. aluminium is extracted by electrolysis. Aluminium is more reactive than iron (has made a comparison in reactivity). ● or The relative reactivity of one metal and reference to cost e.g. aluminium is a more reactive metal and so is expensive to extract. ● The answer communicates ideas showing some evidence of clarity and organisation and uses scientific terminology appropriately. ● Spelling, punctuation and grammar are used with some accuracy. Level 3: 5–6 marks ● A detailed description containing at least three statements referring to relative reactivity of both metals, a method of extraction of at least one metal, and a cost reference e.g. aluminium is more reactive than iron so is extracted by electrolysis which is expensive. ● The answer communicates ideas clearly and coherently uses a range of scientific terminology accurately. ● Spelling, punctuation and grammar are used with few errors. (Total for Question 4 = 10 marks) TOTAL FOR PAPER = 30 MARKS 4 © Pearson Education Ltd 2015. Copying permitted for purchasing institution only. This material is not copyright free.