Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature AQA Level 1/2 Certificate SCIENCE: DOUBLE AWARD Higher Tier Chemistry Paper 2H H Wednesday 15 June 2016 Afternoon Time allowed: 1 hour Materials For this paper you must have: a ruler a calculator the periodic table (enclosed). Instructions Use black ink or black ball-point pen. Fill in the es at the top of this page. Answer all questions. You must answer the questions in the spaces provided. around each page or on blank pages. Do all rough work in this book. Cross through any work you do not want to be marked. Information The marks for questions are shown in brackets. The maximum mark for this paper is 60. You are expected to use a calculator where appropriate. You are reminded of the need for good English and clear presentation in your answers. Question 1(d) should be answered in continuous prose. In this question you will be marked on your ability to: use good English organise information clearly use specialist vocabulary where appropriate. Advice In all calculations, show clearly how you work out your answer. (Jun168404C2H01) G/KL/113139/Jun16/E6 8404/C/2H
2 Answer all questions in the spaces provided. 1 This question is about oxides of metals and oxides of non-metals. 1 (a) Figure 1 shows four areas of the periodic table. Figure 1 A D B C In which area, A, B, C or D, do you find non-metals? 1 (b) A student added an oxide to water. A solution formed. Describe a chemical test the student could use to find out if the solution is acidic or alkaline. Give the substance used for the test and what you would expect to observe. (02)
3 1 (c) Aluminium oxide reacts with acids and alkalis. 1 (c) (i) Use the correct answer from the to complete the sentence. acidic amphoteric basic Aluminium oxide is. 1 (c) (ii) Aluminium oxide contains the ions Al 3+ and O 2 What is the formula of aluminium oxide? Draw a ring around the correct answer. AlO Al 2 O 3 Al 3 O 2 1 (c) (iii) Figure 2 shows a diagram of the electronic structure of an aluminium atom (Al). Complete Figure 2 to show the electronic structure of an aluminium ion (Al 3+ ). Figure 2 Aluminium atom (Al) Aluminium ion (Al 3+ ) 3+ Question 1 continues on the next page Turn over (03)
4 1 (d) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate. The student tested four metal oxides and four non-metal oxides. The student added the oxide to water and tested the ph of any solution produced. The student s results are given in Table 1. Table 1 Oxide Solubility in water ph of solution Sodium oxide Soluble 14 Calcium oxide Soluble 10 Magnesium oxide Slightly soluble 9 Zinc oxide Insoluble Carbon dioxide Soluble 5 Sulfur dioxide Soluble 2 Phosphorus oxide Soluble 1 Silicon dioxide Insoluble (04)
5 The student made the following conclusions. Conclusion 1: All oxides of metals produce alkaline solutions. Conclusion 2: All oxides of non-metals produce acidic solutions. Does the evidence justify these conclusions? Use the information in Table 1 to support your answer. [6 marks] Extra space 12 Turn over (05)
6 2 This question is about reactions that use catalysts. 2 (a) Give two reasons why catalysts are used in industrial processes. 2 (b) Hydrogen peroxide decomposes to produce water and oxygen. Balance the symbol equation for this reaction. H 2 O 2 2 H 2 O + O 2 2 (c) Two students, A and B, investigated the use of manganese oxide as a catalyst in the decomposition of hydrogen peroxide. Student A used the apparatus shown in Figure 3. Figure 3 Bung Gas syringe Hydrogen peroxide Conical flask Manganese oxide The student: removed the bung added hydrogen peroxide solution to the conical flask replaced the bung and started a stopclock measured the volume of oxygen every 10 seconds. (06)
7 Student B used the apparatus shown in Figure 4. Figure 4 Bung Conical flask Test tube Gas syringe Manganese oxide Hydrogen peroxide The student: tipped the conical flask and started a stopclock measured the volume of oxygen every 10 seconds. 2 (c) (i) Give one reason why student B s method gave more accurate results than student A s method. 2 (c) (ii) State the type of error caused by student A s method compared with student B s method. Question 2 continues on the next page Turn over (07)
8 2 (d) The students results are shown in Table 2. Table 2 Time in seconds Student A Volume of oxygen in cm 3 Student B 0 0 0 10 47 52 20 63 68 30 72 77 40 77 82 50 79 84 60 79 84 Student A s results are drawn in the graph in Figure 5. 2 (d) (i) Plot student B s results on the graph in Figure 5. Draw a line of best fit. [3 marks] 100 Figure 5 80 Student A Volume of oxygen in cm 3 60 40 20 0 0 10 20 30 40 Time in seconds 50 60 (08)
9 2 (d) (ii) How does the rate of reaction change between the start and the end of the reaction? Use student A s graph in Figure 5 to justify your answer. 2 (d) (iii) Explain, in terms of particles, why the rate changes as you described in part (d)(ii). 12 Turn over for the next question Turn over (09)
10 3 This question is about the elements in Group 7, the halogens. 3 (a) The elements in Group 7 react with metals to form ions. Give the symbol of the fluoride ion. 3 (b) A student investigated the reactivity of the halogens. The student added a few drops of the potassium halide solution to the halogen solution. Table 3 shows the observations the student made. Table 3 Potassium halide solution (colour) Halogen solution (colour) Chlorine (colourless) Bromine (yellow) Iodine (brown) Potassium chloride (colourless) No colour change No colour change Potassium bromide (colourless) Yellow solution No colour change Potassium iodide (colourless) Brown solution 3 (b) (i) Complete Table 3 to show what the student would see when potassium iodide solution is added to bromine solution. (10)
11 3 (b) (ii) Use the observations in Table 3 to work out the order of reactivity of the three halogens. Give a reason for your order of reactivity. Most reactive Least reactive Reason 3 (b) (iii) Another student forgot to label the beakers of potassium bromide solution and potassium iodide solution. Describe a chemical test the student could do to identify the two solutions, without using solutions of chlorine or bromine. Give the test, and the observations with potassium bromide solution and with potassium iodide solution. [3 marks] Question 3 continues on the next page Turn over (11)
12 3 (c) Chlorine is produced from sodium chloride solution by electrolysis. 3 (c) (i) Complete and balance the half equation to show the production of chlorine at the positive electrode. Cl Cl 2 3 (c) (ii) Why is the production of chlorine in this electrolysis known as oxidation? 3 (c) (iii) Name the two other products of the electrolysis of sodium chloride solution. 12 (12)
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14 4 A student measured the enthalpy change (ΔH) for the reaction between sodium hydroxide solution and sulfuric acid. 4 (a) (i) Complete the word equation for the reaction. sodium hydroxide + sulfuric acid + 4 (a) (ii) This reaction is an example of a neutralisation reaction. Give the ionic equation for a neutralisation reaction. 4 (b) The student used this method. Step 1 Measure 25 cm 3 sodium hydroxide solution into a polystyrene cup. Step 2 Measure the temperature of the sodium hydroxide solution. Step 3 Add 5 cm 3 sulfuric acid and stir the mixture. Step 4 Measure the highest temperature. Step 5 Repeat steps 3 and 4 until a total of 50 cm 3 sulfuric acid has been added. 4 (b) (i) Explain why the student used a polystyrene cup instead of a glass beaker. (14)
15 4 (b) (ii) Figure 6 shows one of the measured temperatures. Figure 6 C 29 28 27 What is the temperature shown in Figure 6? Temperature = C Question 4 continues on the next page Turn over (15)
16 4 (c) Figure 7 shows the student s results. 32 Figure 7 30 28 Temperature in C 26 24 22 20 0 10 20 30 40 Volume of sulfuric acid in cm 3 50 4 (c) (i) Explain why the graph line in Figure 7 goes up and then goes down. [4 marks] (16)
17 4 (c) (ii) Use the graph in Figure 7 to calculate the maximum temperature change of the sodium hydroxide solution during the reaction. Maximum temperature change = C 4 (c) (iii) The maximum temperature change on the graph is when 12.5 cm 3 sulfuric acid has been added to 25 cm 3 sodium hydroxide solution. Calculate the enthalpy change (ΔH) for the reaction, from the equation: ΔH = Maximum temperature change total volume of solution 0.168 [3 marks] Enthalpy change (ΔH) = kj per mole 14 Turn over for the next question Turn over (17)
18 5 A group of students investigated the thermal decomposition of copper carbonate. CuCO 3 (s) CuO (s) + CO 2 (g) 5 (a) The students calculated the mass of copper oxide produced from 0.10 mol of copper carbonate. 5 (a) (i) Calculate the relative formula mass (M r ) of copper carbonate, CuCO 3 Relative atomic masses (A r ): C = 12; O = 16; Cu = 63.5 Relative formula mass (M r ) = 5 (a) (ii) Calculate the mass of 0.10 mol of copper carbonate, CuCO 3 Mass = g 5 (a) (iii) The relative formula mass (M r ) of copper oxide, CuO, is 79.5 Calculate the mass of copper oxide the students should produce from 0.10 mol of copper carbonate. Mass of copper oxide = g (18)
19 5 (b) The students used the following method for this investigation. Measure the mass of a dry test tube. Add 2.00 g of copper carbonate to the test tube. Heat the test tube until there appears to be no further reaction. Measure the mass of the test tube and the solid product. Calculate the mass of the solid product. Repeat the investigation using different masses of copper carbonate. The students did the experiment three times for each different mass of copper carbonate. The students results are shown in Table 4. Table 4 Mass of copper carbonate in g Experiment 1 Mass of solid product in g Experiment 2 Experiment 3 Mean mass of solid product in g 2.00 1.28 1.29 1.30 1.29 4.00 2.56 2.58 2.60 2.58 6.00 4.87 3.86 3.88 8.00 5.15 5.17 5.16 5.16 10.00 6.47 6.48 6.40 6.45 5 (b) (i) Calculate the mean mass of solid product for 6.00 g copper carbonate. Do not include any anomalous result in your calculation. Mean mass of solid product = g Question 5 continues on the next page Turn over (19)
20 5 (b) (ii) The mass of solid product was found to be higher than the expected value. State what could cause this error, assuming that the copper carbonate was pure. Describe how the procedure could be improved to prevent this error. [3 marks] 5 (c) The students drew a graph of their results. A sketch of their graph is shown in Figure 8. Figure 8 Mass of solid product in g 0 0 Mass of copper carbonate in g What is the relationship between the mass of copper carbonate and the mass of solid product? 10 END OF QUESTIONS Copyright 2016 AQA and its licensors. All rights reserved. (20)