1. Focus on what the question is asking rather than just putting down everything you know about a subject. Always show your working! Ensure you answer all parts of the question to maximise your marks. Be careful not to say two opposite statements in the same answer. Do not be afraid to use the information you have been given as part of your answer. Always read the question correctly to ensure that you are answering the question that is being asked rather than one you would like to be asked.

2. C3 Exam Tips Feedback from the examiners The examiner says…

3. From the mark scheme: same general formula (1) same functional group (1) (consecutive) compounds differ by CH 2 (1) gradual variation in physical properties (1) {similar / same} chemical {properties / reactions} (1) ignore same properties/physical properties

4. This test would work for carbon dioxide, but is not specific to carbon dioxide. Only the limewater test is acceptable, so this response did not score.

5. Read the question carefully, it asks you to ‘state how’ but this student has tried to ‘explain why’.

6. I’m lost for words…

8. From the mark scheme: A description including two from effervescence / fizzing / bubbles of gas (1) solid {disappears/clears} /(colourless)solutio n formed (1)

9. Could get more marks

11. Making Esters The ester

12. Draw the structure of a molecule of methanol, CH 3 OH. Show all the covalent bonds. (1 mark) Double check your drawings. Remember how many covalent bonds each atom forms: C 4 O 2 H 1

14. Commonly seen errors, which limited the score to 1 mark, included: the incorrect reagent, often sodium hydroxide or hydrochloric acid, or an extra reagent was added, coupled with a correct result; a correct test stated with no result given; a correct test, but failing to mention either yellow or precipitate; a correct test, but giving the wrong colour precipitate, namely white or cream. 2 (a) Three solids, A, B, and C, are analysed. (i) Solid A is potassium iodide. A small amount of solid A is dissolved in water to form a solution. Describe the test to show that the solution of A contains iodide ions.

15. Mass Moles Relative atomic/ mole cular mass

16. Mass Moles Relative atomic/ mole cular mass If you need to calculate the number of moles

17. Mole Conc Volume

18. Don’t be put off if a calculation seems too simple, check how many marks it is worth.

19. If they want PURE crystals you can’t have any indicator in the solution you leave to evaporate. You need to use the indicator in your titration to find the volume of hydrochloric acid needed, and then repeat without indicator, adding the exact volume.

20. H + + OH -  H 2 O 4 To make pure sodium chloride from sodium hydroxide solution and dilute hydrochloric acid, a titration has to be used. The equation for the reaction is HCl(aq) + NaOH(aq)  NaCl(aq) + H 2 O(l) (b) The reaction above is a neutralisation reaction. Write the ionic equation for the reaction. This question was very poorly answered. Most candidates struggled with writing the ionic equation for neutralisation. It was apparent that very few candidates knew what is meant by an ionic equation, let alone how to write one.

21. Flame tests are commonly used for CATIONS (metals). Precipitate reactions can also be used by reacting the ionic solution with SODIUM HYDROXIDE as most metal hydroxides are insoluble in water. Testing for Cations Dissolves again in an excess of NaOH

22. Testing for the Halogens – This is performed by acidifying the sample with dilute Nitric Acid and then reacting with Silver Nitrate to form a precipitate. – This reaction works by the Halogen displacing the Nitrate in Silver Nitrate with the Halogen. Testing for Ammonium ions (NH 4 + ) – Warm the solution to release the Ammonium ions as a vapour – It will turn damp red litmus paper blue. Testing for anions

24. Convert concentration in g dm -3 into mol dm -3 and vice versa Mass Moles Relative atomic/ mole cular mass All you’re doing is changing g into mol or mol into g.

25. Calculate the concentration of solutions in gdm -3 Just think of it as g/dm 3 g dm 3 So do mass volume

26. To convert from cm 3 to dm 3 divide by a thousand.

27. C2 Higher Paper Summary 2014 Paper Summary In order to improve their performance, candidates should: read all the information in the question carefully and use this to help them to answer the question. practise writing balanced equations from the specification which regularly appear in the examination, including esterification and the correct formulae for esters, the hydration of ethene and ionic equations, especially for neutralisation reactions. revise the correct procedure and results for testing the ions in the specification. learn the names of commonly used indicators for titrations and their correct colour changes, and to avoid the use of universal indicator for titrations. be able to describe the processes occurring in electrolysis reactions in the specification and to explain these in terms of the redox processes occurring, especially for the purification of copper, the electrolysis of molten salts and solutions of salts, and to avoid incorrectly using chlorine ion instead of the correct term, chloride ion.

28. GOOD LUCK FROM ALL THE SCIENCE TEACHERS AND TECHNICIANS