CSEC Chemistry · January 2017 · Paper 2

46 questions and parts from this paper. Open one to see it in full, then practise it on Quelpr and get it marked against the mark scheme.

1. 1(a)1 markDefine the term 'standard solution'.
2. 1(b)1 markComplete Table 1 by calculating the mass of the hydrated iron(II) sulfate used.
3. 1(c)(i)3 marksRecord the final burette volumes from the diagrams in Figure 1 in the appropriate spaces in Table 2.
4. 1(c)(ii)3 marksCalculate the volume of KMnO4 solution used in EACH titration and enter them in Table 2.
5. 1(c)(iii)1 markDetermine the average volume of KMnO4 solution used in the titrations.
6. 1(d)(i)1 markAs shown in the equation, 1 mole MnO4⁻ reacts with 5 moles of Fe²⁺. Using the result in (c)(iv), calculate the number of moles of Fe²⁺ ions in the 25.0 cm³ aliquot that reacted with the MnO4⁻.
7. 1(d)(ii)1 markDetermine the number of moles of Fe²⁺ in the 250.0 cm³ volumetric flask.
8. 1(d)(iv)1 markCalculate the number of moles of KMnO4 in the average volume determined in (c)(iii).
9. 1(e)1 markGiven that 1 mole of FeSO4 contains 1 mole of Fe²⁺ ions, use the result from (d)(ii) to calculate the mass of anhydrous FeSO4 in the 250 cm³ volumetric flask. [The relative molecular mass of anhydrous FeSO4 is 152.]
10. 1(f)1 markCalculate the mass of water in the hydrated FeSO4 using the following formula: Mass of water = mass of hydrated FeSO4 [from (b)] - mass of anhydrous FeSO4 [from (e)].
11. 1(g)1 markCalculate the number of moles of water in the hydrated sample. [The relative molecular mass of water is 18.0.]
12. 1(h)1 markUsing the results from (d)(ii) and (g), calculate the value of n in the formula FeSO4•nH₂O. n = number of moles of water in hydrated sample / number of moles of anhydrous FeSO4.
13. 1(i)2 marksWhat is the colour change at the endpoint of the titration of iron(II) sulfate with potassium manganate(VII)?
14. 1(j)1 markState ONE reason why there was no need to add an indicator to this titration.
15. 1(k)(i)2 marksAqueous sodium hydroxide was added dropwise, and then in excess. Inference: Fe²⁺ ions present.
16. 1(k)(ii)2 marksThe resulting mixture from (i) was left to stand in air. Inference: Fe²⁺ ions oxidized to Fe³⁺.
17. 1(k)(iii)2 marksAqueous barium nitrate was added, followed by dilute nitric acid. Inference: SO4²⁻ ions present.
18. 2(a)(i)2 marksDefine the term 'electrolysis'.
19. 2(a)(ii)2 marksDefine the term 'electroplating'.
20. 2(a)(iii)3 marksList THREE other applications of electrolysis.
21. 2(b)(i)4 marksDraw a fully labelled diagram of the apparatus she should use and state the material from which the electrodes are made.
22. 2(b)(ii)4 marksWrite balanced equations to indicate the reactions which occur at EACH electrode. Equation at anode: Equation at cathode:
23. 3(a)(i)1 markState whether Compound A is an alkane or alkene.
24. 3(a)(ii)1 markState ONE use of Compound A.
25. 3(a)(iii)1 markState ONE condition that is necessary for this reaction to take place.
26. 3(a)(iv)2 marksDraw the FULLY DISPLAYED structural formula of the product (colourless compound) formed when one mole of Compound A reacts with one mole of chlorine gas.
27. 3(a)(v)1 markBriefly describe ONE test that can be used to identify the gaseous by-product.
28. 3(b)(i)2 marksDefine the term 'polymer'.
29. 3(b)(ii)3 marksState the type of polymerization reaction, the name of the polymer formed, and ONE possible use for this polymer.
30. 3(c)(i)1 markName the functional group (link) present in the polymer.
31. 3(c)(ii)2 marksName the type of polymerization reaction that has taken place, and state ONE possible use of these types of polymers.
32. 3(c)(iii)1 markName the by-product that is formed in this polymerization reaction.
33. 4(a)3 marksDefine the term 'isotope' and hence show by calculation that ¹²C and ¹³C are isotopes.
34. 4(b)3 marksState THREE other uses of radioisotopes.
35. 4(c)(i)6 marksState the appropriate group and period to which EACH element, W and X, belongs. Hence, indicate the type of bonding that occurs between W and X and write the formula of the compound formed.
36. 4(c)(ii)3 marksSuggest whether the resulting compound will dissolve in water. Explain your answer.
37. 5(a)2 marksState TWO physical properties of ammonia gas.
38. 5(b)(i)3 marksDraw a labelled diagram to show the apparatus used for the laboratory preparation of ammonia gas.
39. 5(b)(ii)2 marksWrite a balanced chemical equation for the reaction taking place in the laboratory preparation of ammonia gas.
40. 5(b)(iii)3 marksExplain why concentrated sulfuric acid, a typical drying agent, CANNOT be used in this preparation and identify an appropriate alternative drying agent that could be used.
41. 5(c)2 marksBriefly describe a laboratory test for ammonia gas.
42. 5(d)3 marksList THREE harmful effects of excessive nitrates in the environment.
43. 6(a)4 marksState TWO properties of water and explain how EACH property assists in sustaining life on Earth.
44. 6(b)(i)2 marksWrite a balanced equation showing how hard water, formed as stated above, can be softened using sodium carbonate.
45. 6(b)(ii)4 marksName and describe ONE other method by which water can be softened.
46. 6(c)5 marksDescribe a method which can be used to distinguish between hard water and soft water using soap.