Đề thi môn hoá chính thức hệ Cambridge IGCSE™ Chemistry, đề thi bao gồm đề trắc nghiệm (multiple choice) và đề tự luận (Theory). Ngoài ra còn chia hai hệ cơ bản (core) và hệ nâng cao (extended) giúp các bạn học sinh có thể lựa chọn đề phù hợp nhất.
Cambridge IGCSE™ *6863939729* CHEMISTRY0620/33 May/June 2023 Paper Theory (Core) hour 15 minutes 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 80 ● The number of marks for each question or part question is shown in brackets [ ] ● The Periodic Table is printed in the question paper This document has 20 pages Any blank pages are indicated IB23 06_0620_33/2RP © UCLES 2023 [Turn over 1 Fig. 1.1 shows part of the Periodic Table I II III IV V VI VII VIII C N O Li F Al Ca Cr Fe Cu Ar Br I Fig 1.1 Answer the following questions using only the elements in Fig. 1.1 Each symbol of the element may be used once, more than once or not at all Give the symbol of the element that: (a) is present in diamond [1] (b) forms an oxide that contributes to acid rain [1] (c) has an atom with five occupied electron shells [1] (d) forms an ion with a charge of 1+ [1] (e) forms an ion that gives a red-brown precipitate on addition of aqueous ammonia [1] (f) is used in the manufacture of aircraft because of its low density [1] [Total: 6] © UCLES 2023 0620/33/M/J/23 (a) Table 2.1 shows some properties of the halogens Table 2.1 density at room temperature and pressure in g / cm3 halogen melting point in °C boiling point in °C fluorine –220 –188 chlorine –101 bromine –7 +59 3.12 +114 +184 4.93 iodine 0.003 Use the information in Table 2.1 to predict: (i) the boiling point of chlorine ������������������������������������������������������������������������������������������� [1] (ii) the density of fluorine at room temperature and pressure �������������������������������������������� [1] (iii) the physical state of iodine at +100 °C Give a reason for your answer physical state reason [2] (b) Aqueous chlorine reacts with aqueous sodium bromide (i) Complete the word equation for this reaction chlorine + sodium bromide → + [2] (ii) State a test for sodium ions test observations [2] © UCLES 2023 [Total: 8] 0620/33/M/J/23 [Turn over 3 (a) Polluted water can contain harmful substances such as metal compounds, nitrates and sewage (i) Name two other substances present in polluted water which are harmful to aquatic life 1 [2] (ii) State why sewage can cause disease [1] (b) Table 3.1 shows the masses of ions, in mg, present in 1000 cm3 of polluted water Table 3.1 formula of ion mass of ion present in mg / 1000 cm3 of polluted water ammonium NH4+ 1.2 calcium Ca2+ 2.2 chloride Cl – 2.5 HCO3– 13.0 magnesium Mg2+ 1.0 nickel(II) Ni2+ 0.2 nitrate NO3– 0.4 K+ 6.3 silicate SiO32– 8.0 sodium Na+ 12.2 SO42– 0.1 name of ion hydrogencarbonate potassium Answer these questions using information from Table 3.1 (i) Name the positive ion present in the lowest concentration [1] (ii) State the name of the ion SO42– [1] (iii) Calculate the mass of calcium ions present in 250 cm3 of polluted water © UCLES 2023 mass = mg [1] 0620/33/M/J/23 (c) Cobalt(II) chloride can be used to test for the presence of water CoCl 2(s) + 6H2O(l) blue cobalt(II) pink cobalt(II) chloride chloride (i) Describe how pink cobalt(II) chloride can be changed to blue cobalt(II) chloride CoCl 2•6H2O(s) [1] (ii) Choose a word from the list which best describes pink cobalt(II) chloride Draw a circle around your chosen answer anhydrous hydrated liquid reduced[1] (d) Iron reacts with steam to form Fe3O4 and a gas which pops with a lighted splint Complete the symbol equation for this reaction 3Fe + H2O → Fe3O4 + © UCLES 2023 [2] [Total: 10] 0620/33/M/J/23 [Turn over 4 This question is about bromine and compounds of bromine (a) Deduce the number of protons, neutrons and electrons in the bromide ion shown 81 – 35Br number of protons number of neutrons number of electrons [3] (b) Hydrogen bromide decomposes to hydrogen and bromine when heated Fig. 4.1 shows an incomplete reaction pathway diagram for this reaction energy progress of reaction Fig 4.1 (i) Complete Fig. 4.1 by writing these formulae on the diagram: ● 2HBr ● H2 + Br2.[1] (ii) Explain how Fig. 4.1 shows that the reaction is endothermic [1] (iii) Complete this sentence about an endothermic reaction using a word from the list products reactants bromine surroundings An endothermic reaction transfers thermal energy from the © UCLES 2023 0620/33/M/J/23 [1] (c) Hydrobromic acid is formed when hydrogen bromide dissolves in water (i) Write the formula of the ion which is present in all acids [1] (ii) Complete the word equation for the reaction of any acid with any carbonate acid + carbonate → + + [3] (iii) A few drops of litmus indicator are added to a dilute acid State the colour of the solution © UCLES 2023 [1] 0620/33/M/J/23 [Turn over (d) Fig. 4.2 shows the apparatus used for the electrolysis of molten lead(II) bromide using graphite electrodes – power + supply Fig 4.2 (i) Label Fig. 4.2 to show: ● the cathode ● the electrolyte. [2] (ii) Name the products and state the observations at the positive and negative electrodes product at the positive electrode observations at the positive electrode product at the negative electrode observations at the negative electrode [4] (iii) State one property of graphite that makes it useful as an electrode [1] [Total: 18] © UCLES 2023 0620/33/M/J/23 5 This question is about metals (a) Nickel is a transition element Sodium is an element in Group I of the Periodic Table State two differences in the physical properties of nickel compared to sodium [2] (b) Stainless steel is an alloy that is used to make cutlery Give one reason why stainless steel is used to make cutlery [1] (c) Table 5.1 shows some information about the reaction of four metals with oxygen Table 5.1 metal reaction with oxygen gold no reaction lanthanum forms a layer of oxide rapidly but does not burn magnesium burns rapidly to form an oxide nickel forms a layer of oxide slowly but does not burn Put the four metals in order of their reactivity Put the least reactive metal first least reactive most reactive [2] (d) Complete the diagram in Fig. 5.1 to show the electronic configuration of a magnesium atom Mg Fig 5.1 [1] © UCLES 2023 [Total: 6] 0620/33/M/J/23 [Turn over 10 (a) A student investigates the reaction of magnesium with dilute hydrochloric acid at three different temperatures The temperatures are: ● 20 °C ● 30 °C ● 40 °C All other conditions stay the same Table 6.1 shows the time taken for each reaction to finish Table 6.1 temperature / °C time taken for the reaction to finish / s 45 210 95 (i) Complete Table 6.1 by writing the temperatures in the first column. (ii) D escribe the effect on the time taken for the magnesium to finish reacting with dilute hydrochloric acid when the surface area of the magnesium is increased [1] All other conditions stay the same [1] (iii) D escribe the effect on the time taken for the magnesium to finish reacting with dilute hydrochloric acid when the concentration of acid is decreased All other conditions stay the same [1] (b) Describe how crystals of magnesium chloride can be prepared after reacting excess magnesium with dilute hydrochloric acid [2] © UCLES 2023 0620/33/M/J/23 16 (iv) Pure water has a neutral pH value Choose from the list, the pH value that is neutral Draw a circle around your chosen answer pH pH pH pH 14[1] (v) A crystal of blue copper(II) sulfate is placed at the bottom of a beaker of water as shown in Fig. 8.2 water crystal of copper(II) sulfate at first after one day Fig 8.2 After one day, the blue colour has spread throughout the water in the beaker Explain these results in terms of the kinetic particle theory [3] [Total: 13] © UCLES 2023 0620/33/M/J/23 17 BLANK PAGE © UCLES 2023 0620/33/M/J/23 18 BLANK PAGE © UCLES 2023 0620/33/M/J/23 19 BLANK PAGE 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 2023 0620/33/M/J/23 © UCLES 2023 12 V Cr Mn Co 27 Ni 28 Cu 29 Zn 30 Fe 57–71 56 55 0620/33/M/J/23 104 88 – 90 89 232 thorium actinium – Th Ac 140 cerium 139 lanthanum 59 231 protactinium Pa 91 141 praseodymium Pr – 58 Ce – Db dubnium Rf rutherfordium La 57 actinoids 105 181 tantalum Ta 73 93 niobium Nb 41 51 vanadium 238 uranium U 92 144 neodymium 60 Nd – Sg seaborgium 106 184 tungsten W 74 96 molybdenum Mo 42 52 chromium – neptunium Np 93 – promethium 61 Pm – Bh bohrium 107 186 rhenium Re 75 – technetium Tc 43 55 manganese – plutonium Pu 94 150 samarium 62 Sm – Hs hassium 108 190 osmium Os 76 101 ruthenium Ru 44 56 iron – americium Am 95 152 europium 63 Eu – Mt meitnerium 109 192 iridium Ir 77 103 rhodium Rh 45 59 cobalt – curium Cm 96 157 gadolinium 64 Gd – Ds darmstadtium 110 195 platinum Pt 78 106 palladium Pd 46 59 nickel The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.) actinoids lanthanoids – Ra radium Fr francium 89–103 178 87 137 hafnium 133 barium Hf caesium lanthanoids Ba 72 91 zirconium Zr 40 48 titanium Cs 89 yttrium 88 strontium 85 rubidium Y 39 45 Sr 38 40 Ca Rb 37 39 K scandium – berkelium Bk 97 159 terbium 65 Tb – Rg roentgenium 111 gold 197 Au 79 108 silver Ag 47 64 copper – californium Cf 98 163 dysprosium 66 Dy – Cn copernicium 112 201 mercury Hg 80 112 cadmium Cd 48 65 zinc calcium Ti 26 potassium Sc 25 31 24 – einsteinium Es 99 165 holmium 67 Ho – Nh nihonium 113 204 thallium Tl 81 115 indium In 49 70 gallium Ga 27 20 24 19 23 aluminium Al 13 11 boron magnesium 23 sodium 22 B C N O VI F VII VIII – fermium Fm 100 167 erbium 68 Er – Fl flerovium 114 lead 207 Pb 82 tin 119 Sn 50 73 germanium Ge 32 28 silicon Si 14 12 carbon – mendelevium Md 101 169 thulium 69 Tm – Mc moscovium 115 209 bismuth Bi 83 122 antimony Sb 51 75 arsenic As 33 31 phosphorus P 15 14 nitrogen – nobelium No 102 173 ytterbium 70 Yb – Lv livermorium 116 – polonium Po 84 128 tellurium Te 52 79 selenium Se 34 32 sulfur S 16 16 oxygen – Lr lawrencium 103 175 lutetium 71 Lu – Ts tennessine 117 – astatine At 85 127 iodine I 53 80 bromine Br 35 35.5 chlorine Cl 17 19 fluorine – oganesson Og – 118 radon 86 Rn 131 xenon 54 Xe 84 krypton 36 Kr 40 argon 18 Ar 20 neon Ne 10 helium V hydrogen IV He Mg 21 relative atomic mass name atomic symbol atomic number Key III H Na 11 Be beryllium Li lithium II I Group The Periodic Table of Elements 20 Cambridge IGCSE™ CHEMISTRY 0620/33 Paper Theory (Core) May/June 2023 MARK SCHEME Maximum Mark: 80 Published This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination It shows the basis on which Examiners were instructed to award marks It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers Cambridge International will not enter into discussions about these mark schemes Cambridge International is publishing the mark schemes for the May/June 2023 series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components This document consists of 10 printed pages © UCLES 2023 [Turn over 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED Generic Marking Principles May/June 2023 These general marking principles must be applied by all examiners when marking candidate answers They should be applied alongside the specific content of the mark scheme or generic level descriptors for a question Each question paper and mark scheme will also comply with these marking principles GENERIC MARKING PRINCIPLE 1: Marks must be awarded in line with: the specific content of the mark scheme or the generic level descriptors for the question the specific skills defined in the mark scheme or in the generic level descriptors for the question the standard of response required by a candidate as exemplified by the standardisation scripts GENERIC MARKING PRINCIPLE 2: Marks awarded are always whole marks (not half marks, or other fractions) GENERIC MARKING PRINCIPLE 3: Marks must be awarded positively: marks are awarded for correct/valid answers, as defined in the mark scheme However, credit is given for valid answers which go beyond the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate marks are awarded when candidates clearly demonstrate what they know and can marks are not deducted for errors marks are not deducted for omissions answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the question as indicated by the mark scheme The meaning, however, should be unambiguous GENERIC MARKING PRINCIPLE 4: Rules must be applied consistently, e.g in situations where candidates have not followed instructions or in the application of generic level descriptors © UCLES 2023 Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2023 GENERIC MARKING PRINCIPLE 5: Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may be limited according to the quality of the candidate responses seen) GENERIC MARKING PRINCIPLE 6: Marks awarded are based solely on the requirements as defined in the mark scheme Marks should not be awarded with grade thresholds or grade descriptors in mind Science-Specific Marking Principles Examiners should consider the context and scientific use of any keywords when awarding marks Although keywords may be present, marks should not be awarded if the keywords are used incorrectly The examiner should not choose between contradictory statements given in the same question part, and credit should not be awarded for any correct statement that is contradicted within the same question part Wrong science that is irrelevant to the question should be ignored Although spellings not have to be correct, spellings of syllabus terms must allow for clear and unambiguous separation from other syllabus terms with which they may be confused (e.g ethane / ethene, glucagon / glycogen, refraction / reflection) The error carried forward (ecf) principle should be applied, where appropriate If an incorrect answer is subsequently used in a scientifically correct way, the candidate should be awarded these subsequent marking points Further guidance will be included in the mark scheme where necessary and any exceptions to this general principle will be noted ‘List rule’ guidance For questions that require n responses (e.g State two reasons …): The response should be read as continuous prose, even when numbered answer spaces are provided Any response marked ignore in the mark scheme should not count towards n Incorrect responses should not be awarded credit but will still count towards n Read the entire response to check for any responses that contradict those that would otherwise be credited Credit should not be awarded for any responses that are contradicted within the rest of the response Where two responses contradict one another, this should be treated as a single incorrect response Non-contradictory responses after the first n responses may be ignored even if they include incorrect science © UCLES 2023 Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED May/June 2023 Calculation specific guidance Correct answers to calculations should be given full credit even if there is no working or incorrect working, unless the question states ‘show your working’ For questions in which the number of significant figures required is not stated, credit should be awarded for correct answers when rounded by the examiner to the number of significant figures given in the mark scheme This may not apply to measured values For answers given in standard form (e.g a 10n) in which the convention of restricting the value of the coefficient (a) to a value between and 10 is not followed, credit may still be awarded if the answer can be converted to the answer given in the mark scheme Unless a separate mark is given for a unit, a missing or incorrect unit will normally mean that the final calculation mark is not awarded Exceptions to this general principle will be noted in the mark scheme Guidance for chemical equations Multiples / fractions of coefficients used in chemical equations are acceptable unless stated otherwise in the mark scheme State symbols given in an equation should be ignored unless asked for in the question or stated otherwise in the mark scheme © UCLES 2023 Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED Question Answer May/June 2023 Marks 1(a) C 1(b) N 1(c) I 1(d) Li 1(e) Fe 1(f) Al Question Answer Marks 2(a)(i) values between –100 °C and +10 °C (inclusive of these values) 2(a)(ii) values lower than 0.003 2(a)(iii) solid (1) 100 °C is lower than the melting point / the melting point is above 100 °C (1) 2(b)(i) bromine (1) sodium chloride (1) 2(b)(ii) flame test / put sodium (compound) in (non-luminous) flame (1) (flame colour) yellow (1) © UCLES 2023 Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED Question 3(a)(i) Answer mark each for any two of: May/June 2023 Marks plastics phosphates microbes 3(a)(ii) contains harmful microbes 3(b)(i) nickel 3(b)(ii) sulfate 3(b)(iii) 0.55 (mg) 3(c)(i) heat 3(c)(ii) hydrated 4(H2O) (1) 3(d) (4) H2 (1) © UCLES 2023 Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED Question 4(a) Answer protons: 35 (1) May/June 2023 Marks neutrons: 46 (1) electrons: 36 (1) 4(b)(i) 2HBr on left horizontal line AND H2 + Br2 on right horizontal line 4(b)(ii) the energy of the reactant is lower than the energy of the products / the energy of HBr is lower than the energy of H2 + Br2 / the energy of the products is greater than the energy of the reactants 4(b)(iii) surroundings 4(c)(i) H+ 4(c)(ii) salt (1) carbon dioxide (1) water (1) 4(c)(iii) red / pink 4(d)(i) left hand electrode labelled cathode (1) electrolyte labelled (1) 4(d)(ii) product at anode: bromine (1) observations at anode: red-brown fumes / brown gas / (red-brown) bubbles (1) product at cathode: lead (1) observations at anode: grey solid / grey deposit / silver solid / silver deposit (1) 4(d)(iii) © UCLES 2023 conducts electricity / inert Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED Question 5(a) Answer mark each for any two of: May/June 2023 Marks nickel has a high melting point / boiling point nickel has a high density nickel is strong / hard 5(b) hard / resistant to corrosion / strong 5(c) gold nickel lanthanum magnesium (1) if marks not scored: mark for pair reversed (consecutive) OR magnesium lanthanum nickel gold 5(d) electronic configuration shown as 2,8,2 Question Answer Marks 6(a)(i) 40 °C 20 °C 30 °C 6(a)(ii) takes shorter time / less time taken 6(a)(iii) takes longer time / more time taken filter (off excess magnesium) (1) 6(b) heat until point of crystallisation / heat until form saturated solution 6(c) © UCLES 2023 first box down ticked (ammonium sulfate) Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED Question Answer May/June 2023 Marks 7(a)(i) circle around C=C bond 7(a)(ii) C4H8O 7(a)(iii) aqueous bromine / bromine water (1) saturated: remains orange / no colour change (1) unsaturated: decolourises / turns colourless (1) 7(b)(i) CnH2n+1OH 7(b)(ii) H H │ │ H–C–C–O–H │ │ H H 116 (2) 7(c) if marks not scored mark for 32 (for O) OR 12 (for H) 7(d) mark each for any two of: 7(e) 25–35 °C (inclusive of these values) yeast absence of oxygen / anaerobic sodium ethanoate (1) hydrogen (1) © UCLES 2023 Page of 10 0620/33 Cambridge IGCSE – Mark Scheme PUBLISHED Question 8(a) 8(b) Answer mark each for any of: not malleable / brittle not ductile poor electrical conductor low melting point / low boiling point 8(c)(i) Marks mark each for two of: May/June 2023 planting (more) trees reduction in livestock farming decreasing use of fossil fuels / increasing use of hydrogen / renewable energy pair of electrons between each H and O and no other electrons on H (1) non-bonding electrons on O (1) 8(c)(ii) low melting points / low boiling points (1) not conduct electricity / do not conduct heat (1) 8(c)(iii) a substance that dissolves a solute 8(c)(iv) pH 7 8(c)(v) mark each for any of: © UCLES 2023 copper sulfate dissolves / particles go into solution diffusion particles in (constant) movement / particles collide / molecules travel (movement of) particles is random/particles (move) in every direction particles spread out / particles mix (particles spread) from higher concentration to lower concentration / down concentration gradient Page 10 of 10