Cambridge IGCSE Chemistry Past Paper PDF October/November 2024

* 0000800000001 * Cambridge IGCSE™ Olutimi *7218503662* CHEMISTRY 0620/61 Paper 6 Alternative to Practical...

* 0000800000001 * Cambridge IGCSE™ Olutimi *7218503662* CHEMISTRY 0620/61 Paper 6 Alternative to Practical October/November 2024 1 hour You must answer on the question paper. No additional materials are needed. INSTRUCTIONS Answer all questions. Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs. Write your name, centre number and candidate number in the boxes at the top of the page. Write your answer to each question in the space provided. Do not use an erasable pen or correction fluid. Do not write on any bar codes. You may use a calculator. You should show all your working and use appropriate units. INFORMATION The total mark for this paper is 40. The number of marks for each question or part question is shown in brackets [ ]. Notes for use in qualitative analysis are provided in the question paper. This document has 16 pages. Any blank pages are indicated. IB24 11_0620_61/4RP © UCLES 2024 [Turn over  * 0000800000002 * 2 DO NOT WRITE IN THIS MARGIN 1 A student has a mixture of copper(II) carbonate powder and crystals of sodium sulfate. Copper(II) carbonate is insoluble in water. Sodium sulfate is soluble in water. The student tries to obtain pure copper(II) carbonate and crystals of pure sodium sulfate from the mixture. Fig. 1.1 shows four of the steps the student carries out. step 1 step 2 Add distilled water to Filter the mixture. the mixture and stir. residue DO NOT WRITE IN THIS MARGIN filtrate step 3 step 4 Heat the filtrate from step 2 Leave the residue on the filter paper until crystals start to form. from step 2 in a warm place to dry. residue DO NOT WRITE IN THIS MARGIN heat filter paper Fig. 1.1 (a) State what happens to the sodium sulfate in step 1. dissolves in.............................................................................................................................................. water DO NOT WRITE IN THIS MARGIN (b) State what is removed from the filtrate in step 3............................................................................................................................................... water (c) Describe what must be done after the filtrate has been heated in step 3 to obtain a larger amount of sodium sulfate crystals. leave it to cool.................................................................................................................................................................................................................................................................................................. DO NOT WRITE IN THIS MARGIN © UCLES 2024 0620/61/O/N/24  * 0000800000003 * 3 DO NOT WRITE IN THIS MARGIN (d) (i) State what must be done to the residue before it is allowed to dry in step 4 to obtain pure copper(II) carbonate. Wash it with distilled water.................................................................................................................................................................................................................................................................................... (ii) Identify the substance removed from the copper(II) carbonate in (d)(i). sodium sulfate....................................................................................................................................... DO NOT WRITE IN THIS MARGIN [Total: 5] DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN © UCLES 2024 0620/61/O/N/24 [Turn over © UCLES 2024 * 0000800000004 * 4 0620/61/O/N/24 BLANK PAGE DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN  * 0000800000005 * 5 DO NOT WRITE IN THIS MARGIN 2 A student investigates the reaction between aqueous magnesium sulfate and aqueous barium nitrate. A precipitate of barium sulfate forms in the reaction. The student does eight experiments. Experiment 1 Fill a burette with aqueous magnesium sulfate. Run some of the aqueous magnesium sulfate out of the burette so that the level of the aqueous magnesium sulfate is on the burette scale. Fill a second burette with aqueous barium nitrate. Run some of the aqueous barium nitrate out of the burette so that the level of the aqueous barium nitrate is on the burette scale. DO NOT WRITE IN THIS MARGIN Add 4.0 cm3 of aqueous magnesium sulfate from the first burette into a 10 cm3 measuring cylinder. Add 1.0 cm3 of aqueous barium nitrate from the second burette into the same measuring cylinder. Place a stopper in the top of the measuring cylinder and invert the measuring cylinder several times. Leave the measuring cylinder to stand for 15 minutes. Record the level of the precipitate on the measuring cylinder scale. Rinse the measuring cylinder with distilled water. Experiment 2 DO NOT WRITE IN THIS MARGIN Repeat Experiment 1 using 1.5 cm3 of aqueous barium nitrate instead of 1.0 cm3. Experiment 3 Repeat Experiment 1 using 2.5 cm3 of aqueous barium nitrate instead of 1.0 cm3. Experiment 4 Repeat Experiment 1 using 3.0 cm3 of aqueous barium nitrate instead of 1.0 cm3. Experiment 5 Repeat Experiment 1 using 3.5 cm3 of aqueous barium nitrate instead of 1.0 cm3. DO NOT WRITE IN THIS MARGIN Experiment 6 Repeat Experiment 1 using 4.5 cm3 of aqueous barium nitrate instead of 1.0 cm3. Experiment 7 Repeat Experiment 1 using 5.0 cm3 of aqueous barium nitrate instead of 1.0 cm3. Experiment 8 Repeat Experiment 1 using 5.5 cm3 of aqueous barium nitrate instead of 1.0 cm3. DO NOT WRITE IN THIS MARGIN © UCLES 2024 0620/61/O/N/24 [Turn over  * 0000800000006 * 6 DO NOT WRITE IN THIS MARGIN (a) Use the information in the description of the experiments and the measuring cylinder diagrams to complete Table 2.1. Table 2.1 experiment 1 2 3 4 5 6 7 8 volume of aqueous 4.0 magnesium 04 04 04 04 04 04 0 4..... sulfate / cm3.. DO NOT WRITE IN THIS MARGIN volume of aqueous 1.0 barium nitrate 1 5. 25. 3 0 3 5 45. 5 0. 5 5. / cm3. cm3 cm3 cm3 cm3 cm3 cm3 cm3 cm3 10 10 10 10 10 10 10 10 9 9 9 9 9 9 9 9 8 8 8 8 8 8 8 8 DO NOT WRITE IN THIS MARGIN 7 7 7 7 7 7 7 7 measuring 6 6 6 6 6 6 6 6 cylinder diagram 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3 solution 2 2 2 2 2 2 2 2 DO NOT WRITE IN THIS MARGIN 1 1 1 1 1 1 1 1 precipitate level of precipitate on the measuring 1.2 1 833 64. 24 64 64. 6 cylinder scale.... / cm3 DO NOT WRITE IN THIS MARGIN © UCLES 2024 0620/61/O/N/24  * 0000800000007 * 7 DO NOT WRITE IN THIS MARGIN (b) Complete a suitable scale on the y-axis and plot the results from Experiments 1 to 8 on Fig. 2.1. Draw two straight lines of best fit through your points. The first straight line should be for the first five experiments and must be extended to pass through (0,0). The second straight line should be for the last three experiments and must be horizontal. Extend the straight lines so that they cross each other. 10 0.. 0- 9 8 0. - DO NOT WRITE IN THIS MARGIN 70 - : 6 0-. level of precipitate on the measuring 5 0-. cylinder scale / cm3 - 4 0-. 3 2 0- DO NOT WRITE IN THIS MARGIN. X X 10 - + X 0.0 28 0.0 1.0 2.0 3.0 4.0 5.0 6.0 volume of aqueous barium nitrate / cm3 Fig. 2.1 (c) Use Fig. 2.1 to deduce the level of precipitate on the measuring cylinder scale when the experiment is repeated using 2.8 cm3 of aqueous barium nitrate. DO NOT WRITE IN THIS MARGIN Show clearly on Fig. 2.1 how you worked out your answer. 3 4 level of precipitate =............................... cm3 (d) The student repeats the experiment using 6.5 cm3 of aqueous barium nitrate. Predict the level of precipitate on the measuring cylinder scale. Explain your answer. 4 6 DO NOT WRITE IN THIS MARGIN prediction.................................................................................................................................... All the magnesium sulfate explanation................................................................................................................................ has reacted.................................................................................................................................................... © UCLES 2024 0620/61/O/N/24 [Turn over  * 0000800000008 * 8 DO NOT WRITE IN THIS MARGIN (e) Sketch on Fig. 2.1 the graph obtained if all of the experiments are repeated using aqueous barium nitrate of half the concentration used in Experiments 1 to 8. (f) Suggest why the measuring cylinder is inverted several times after the aqueous barium nitrate is added. To mix the reactions and so that.................................................................................................................................................... The concentration is.............................................................................................................................................. uniform DO NOT WRITE IN THIS MARGIN (g) Suggest why the measuring cylinder is left to stand before the level of the precipitate is recorded. So the precipitate can fall to the.................................................................................................................................................... bottom.............................................................................................................................................. (h) The volumes of both aqueous solutions are measured using burettes. (i) Give a reason why burettes are used rather than measuring cylinders. DO NOT WRITE IN THIS MARGIN burett more accurate than a............................................................................................................................................. a is measuring cylinder....................................................................................................................................... (ii) Suggest why burettes are used rather than volumetric pipettes. the volumes are not fixed.................................................................................................................................................................................................................................................................................... [Total: 19] DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN © UCLES 2024 0620/61/O/N/24  * 0000800000009 * 9 DO NOT WRITE IN THIS MARGIN 3 A student tests two solids: solid T and solid U. Tests on solid T Solid T is lithium sulfite. Complete the expected observations. (a) The student carries out a flame test on solid T. red flame colour observations........................................................................................................................ DO NOT WRITE IN THIS MARGIN The student dissolves the remaining solid T in water to form solution T. The student divides solution T into two portions. (b) The student adds the first portion of solution T to a test-tube containing acidified aqueous potassium manganate(VII). State the colour change. colories : purple from................................................................ to................................................................ DO NOT WRITE IN THIS MARGIN (c) (i) To the second portion of solution T, the student adds excess dilute nitric acid. ↑ The gas produced turns filter paper soaked in acidified aqueous potassium manganate(VII) white. Identify the gas produced. sulfur dioxide , Sow....................................................................................................................................... (ii) To the solution produced in (c)(i), the student adds aqueous barium nitrate. no change observations................................................................................................................. DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN © UCLES 2024 0620/61/O/N/24 [Turn over  * 0000800000010 * 10 DO NOT WRITE IN THIS MARGIN Tests on solid U Solid U contains one cation and one anion. Table 3.1 shows the tests and the student’s observations for solid U. The student dissolves solid U in distilled water to form solution U. The student then divides solution U into three portions. Table 3.1 tests observations DO NOT WRITE IN THIS MARGIN test 1 To the first portion of solution U, add a few green precipitate drops of aqueous ammonia. test 2 To the second portion of solution U, add 1 cm3 yellow precipitate of dilute nitric acid followed by a few drops of aqueous silver nitrate. test 3 DO NOT WRITE IN THIS MARGIN To the third portion of solution U, add 1 cm3 of the solution turns brown aqueous chlorine. (d) Identify two cations that the tests and observations in Table 3.1 show could be in solid U. iron , chromium.................................................................................................................................................................................................................................................................................................. DO NOT WRITE IN THIS MARGIN (e) Describe an additional test that the student could do to confirm which one of the two cations identified in (d) is in solid U. Give the expected result for one of the cations. add ageous sodium hydroxide test............................................................................................................................................. cation chromium......................................................................................................................................... it forms a solution and the precipitate dissolves result.......................................................................................................................................... (f) Identify the anion in solid U. DO NOT WRITE IN THIS MARGIN iodide.............................................................................................................................................. [Total: 10] © UCLES 2024 0620/61/O/N/24  * 0000800000011 * 11 DO NOT WRITE IN THIS MARGIN 4 Beetroot is a coloured vegetable. The colour is caused by a mixture of water-soluble coloured compounds. Plan an experiment to find how many water-soluble coloured compounds there are in a beetroot. Include in your plan: how to extract the coloured compounds from a beetroot how to separate the mixture of coloured compounds ↑ how the results show how many coloured compounds there are in a beetroot. You are provided with a beetroot, distilled water and common laboratory apparatus. DO NOT WRITE IN THIS MARGIN........................................................................................................................................................... 1)........................................................................................................................................................... crush the beetroot 2) with mortar........................................................................................................................................................... 3) and water........................................................................................................................................................... 4) place a drop of the liquid on........................................................................................................................................................... chromatography paper........................................................................................................................................................... & dip DO NOT WRITE IN THIS MARGIN I the bottom of the paper........................................................................................................................................................... in water 6) the number of coloured substances........................................................................................................................................................... will be equal to the number........................................................................................................................................................... of spots............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................. 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DO NOT WRITE IN THIS MARGIN........................................................................................................................................................................................................................................................................................................................................................................................................................................................................... © UCLES 2024 0620/61/O/N/24 [Turn over © UCLES 2024 * 0000800000012 * 12 0620/61/O/N/24 BLANK PAGE DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN  DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN © UCLES 2024 * 0000800000013 * 13 0620/61/O/N/24 BLANK PAGE © UCLES 2024 * 0000800000014 * 14 0620/61/O/N/24 BLANK PAGE DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN  * 0000800000015 * 15 DO NOT WRITE IN THIS MARGIN Notes for use in qualitative analysis Tests for anions anion test test result carbonate, CO32– add dilute acid, then test for carbon effervescence, carbon dioxide dioxide gas produced chloride, Cl – acidify with dilute nitric acid, then white ppt. [in solution] add aqueous silver nitrate DO NOT WRITE IN THIS MARGIN bromide, Br – acidify with dilute nitric acid, then cream ppt. [in solution] add aqueous silver nitrate iodide, I– acidify with dilute nitric acid, then yellow ppt. [in solution] add aqueous silver nitrate nitrate, NO3– add aqueous sodium hydroxide, ammonia produced [in solution] then aluminium foil; warm carefully sulfate, SO42– acidify with dilute nitric acid, then white ppt. [in solution] add aqueous barium nitrate sulfite, SO32– add a small volume of acidified the acidified aqueous potassium aqueous potassium manganate(VII) manganate(VII) changes colour DO NOT WRITE IN THIS MARGIN from purple to colourless Tests for aqueous cations cation effect of aqueous sodium hydroxide effect of aqueous ammonia aluminium, Al 3+ white ppt., soluble in excess, giving white ppt., insoluble in excess a colourless solution ammonium, NH4+ ammonia produced on warming – calcium, Ca2+ white ppt., insoluble in excess no ppt. or very slight white ppt. chromium(III), Cr3+ green ppt., soluble in excess green ppt., insoluble in excess DO NOT WRITE IN THIS MARGIN copper(II), Cu2+ light blue ppt., insoluble in excess light blue ppt., soluble in excess, giving a dark blue solution iron(II), Fe2+ green ppt., insoluble in excess, green ppt., insoluble in excess, ppt. turns brown near surface on ppt. turns brown near surface on standing standing iron(III), Fe3+ red-brown ppt., insoluble in excess red-brown ppt., insoluble in excess zinc, Zn2+ white ppt., soluble in excess, giving white ppt., soluble in excess, giving a colourless solution a colourless solution DO NOT WRITE IN THIS MARGIN © UCLES 2024 0620/61/O/N/24  * 0000800000016 * 16 DO NOT WRITE IN THIS MARGIN Tests for gases gas test and test result ammonia, NH3 turns damp red litmus paper blue carbon dioxide, CO2 turns limewater milky chlorine, Cl 2 bleaches damp litmus paper hydrogen, H2 ‘pops’ with a lighted splint oxygen, O2 relights a glowing splint DO NOT WRITE IN THIS MARGIN sulfur dioxide, SO2 turns acidified aqueous potassium manganate(VII) from purple to colourless Flame tests for metal ions metal ion flame colour lithium, Li+ red sodium, Na+ yellow potassium, K+ lilac calcium, Ca2+ orange-red DO NOT WRITE IN THIS MARGIN barium, Ba2+ light green copper(II), Cu2+ blue-green DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. © UCLES 2024 0620/61/O/N/24  * 0000800000016 * 16 DO NOT WRITE IN THIS MARGIN Tests for gases gas test and test result ammonia, NH3 turns damp red litmus paper blue carbon dioxide, CO2 turns limewater milky chlorine, Cl 2 bleaches damp litmus paper hydrogen, H2 ‘pops’ with a lighted splint oxygen, O2 relights a glowing splint DO NOT WRITE IN THIS MARGIN sulfur dioxide, SO2 turns acidified aqueous potassium manganate(VII) from purple to colourless Flame tests for metal ions metal ion flame colour lithium, Li+ red sodium, Na+ yellow potassium, K+ lilac calcium, Ca2+ orange-red DO NOT WRITE IN THIS MARGIN barium, Ba2+ light green copper(II), Cu2+ blue-green DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. © UCLES 2024 0620/61/O/N/24  * 0000800000016 * 16 DO NOT WRITE IN THIS MARGIN Tests for gases gas test and test result ammonia, NH3 turns damp red litmus paper blue carbon dioxide, CO2 turns limewater milky chlorine, Cl 2 bleaches damp litmus paper hydrogen, H2 ‘pops’ with a lighted splint oxygen, O2 relights a glowing splint DO NOT WRITE IN THIS MARGIN sulfur dioxide, SO2 turns acidified aqueous potassium manganate(VII) from purple to colourless Flame tests for metal ions metal ion flame colour lithium, Li+ red sodium, Na+ yellow potassium, K+ lilac calcium, Ca2+ orange-red DO NOT WRITE IN THIS MARGIN barium, Ba2+ light green copper(II), Cu2+ blue-green DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. © UCLES 2024 0620/61/O/N/24