Cambridge IGCSE Chemistry (9-1) 0971 — 2021 Oct/Nov Paper 2 · Variant 2
0971/22/O/N/21 · 40 questions · 40 marks · ≈45 min
The question paper and its mark scheme, free to read here and free to download. This is Cambridge’s own paper, exactly as it was sat.
Question paper16 pages
Mark scheme3 pages
Answers below. Sit the paper first if you are practising.
Questions as text
Q1 · An experiment is set up as shown
1 An experiment is set up as shown. cotton wool soaked cotton wool soaked in ammonia in hydrochloric acid After several minutes, a white ring of ammonium chloride appears as shown. ammonium chloride Which statement explains the observation after several minutes? A Ammonia gas diffuses faster than hydrogen chloride gas because its molecules have a lower molecular mass. B Ammonia gas diffuses faster than hydrogen chloride gas because its molecules have a higher molecular mass. C Ammonia gas diffuses slower than hydrogen chloride gas because its molecules have a lower molecular mass. D Ammonia gas diffuses slower than hydrogen chloride gas because its molecules have a higher molecular mass.
Mark scheme: A
Q2 · A student put exactly 25.00 cm3 of dilute hydrochloric acid into a conical flask
2 A student put exactly 25.00 cm3 of dilute hydrochloric acid into a conical flask. The student added 2.5 g of solid sodium carbonate and measured the change in temperature of the mixture. Which apparatus does the student need to use? A balance, measuring cylinder, thermometer B balance, pipette, stopwatch C balance, pipette, thermometer D burette, pipette, thermometer
Mark scheme: C
Q3 · A student separates sugar from pieces of broken glass by dissolving the sugar in water…
3 A student separates sugar from pieces of broken glass by dissolving the sugar in water and filtering off the broken glass. filtrate What is the filtrate? A broken glass only B broken glass and sugar solution C pure water D sugar solution
Mark scheme: D
Q4 · How many protons, neutrons and electrons are there in one atom of the isotope 27 13Al ?
4 How many protons, neutrons and electrons are there in one atom of the isotope 27 13Al ? protons neutrons electrons A 13 13 13 B 13 14 13 C 14 13 13 D 14 14 13
Mark scheme: B
Q5 · Which description of brass is correct?
5 Which description of brass is correct? A alloy B compound C element D non-metal
Mark scheme: A
Q6 · Some properties of diamond are shown
6 Some properties of diamond are shown. 1 It is very hard. 2 Every atom forms four bonds. 3 It does not conduct electricity. Which properties are also shown by silicon(IV) oxide? A 1 only B 1 and 2 C 1 and 3 D 2 and 3
Mark scheme: C
Q7 · Which statement describes the attractive forces between molecules?
7 Which statement describes the attractive forces between molecules? A They are strong covalent bonds which hold molecules together. B They are strong ionic bonds which hold molecules together. C They are weak forces formed between covalently-bonded molecules. D They are weak forces which hold ions together in a lattice.
Mark scheme: C
Q8 · Which substance is described as a macromolecule?
8 Which substance is described as a macromolecule? A ammonia B graphite C iron D sodium chloride
Mark scheme: B
Q9 · The equation for the reaction of sodium with water is shown
9 The equation for the reaction of sodium with water is shown. 2Na + 2H2O 2NaOH + H2 What is the volume of hydrogen gas, measured at r.t.p., produced when 18.4 g of sodium reacts with excess water? A 9.6 dm3 B 15.0 dm3 C 19.2 dm3 D 30.0 dm3
Mark scheme: A
Q10 · Iron can be electroplated with zinc to make it resistant to corrosion
10 Iron can be electroplated with zinc to make it resistant to corrosion. Which row about electroplating iron with zinc is correct? positive electrode negative electrode electrolyte (anode) (cathode) A iron zinc iron nitrate B iron zinc zinc nitrate C zinc iron iron nitrate D zinc iron zinc nitrate
Mark scheme: D
Q11 · Chlorine reacts with ethane to produce chloroethane and hydrogen chloride
11 Chlorine reacts with ethane to produce chloroethane and hydrogen chloride. H H H H H C C H + Cl Cl H C C Cl + H Cl H H H H The reaction is exothermic. The bond energies are shown in the table. bond energy bond in kJ / mol C–Cl +340 C–C +350 C–H +410 Cl –Cl +240 H–Cl +430 What is the energy change for the reaction? A –1420 kJ / mol B –120 kJ / mol C +120 kJ / mol D +1420 kJ / mol
Mark scheme: B
Q12 · Chlorine gas is bubbled into aqueous potassium iodide
12 Chlorine gas is bubbled into aqueous potassium iodide. What is the ionic equation for the reaction that takes place? A Cl + I– Cl – + I B Cl 2 + 2I– Cl 2 – + I2 C Cl 2 + 2I– 2Cl – + I2 D Cl 2 + 2I– 2Cl – + 2I
Mark scheme: C
Q13 · Concentrated aqueous sodium chloride is electrolysed
13 Concentrated aqueous sodium chloride is electrolysed. Which equation represents the reaction at the cathode? A Na+ + e– Na B 2O2– O2 + 4e– C 2H+ + 2e– H2 D 2Cl – Cl 2 + 2e–
Mark scheme: C
Q14 · Which statements about hydrogen are correct?
14 Which statements about hydrogen are correct? 1 When hydrogen is burned, heat energy is released. 2 When hydrogen is used in a fuel cell, electrical energy is generated. 3 When hydrogen is used as a fuel, water is the only product. A 1, 2 and 3 B 1 and 2 only C 1 only D 3 only
Mark scheme: A
Q15 · Solid X is heated strongly
15 Solid X is heated strongly. The colour of the solid changes from blue to white. What is solid X? A anhydrous cobalt(II) chloride B calcium carbonate C hydrated copper(II) sulfate D lead(II) bromide
Mark scheme: C
Q16 · Iron(II) chloride solution reacts with chlorine gas
16 Iron(II) chloride solution reacts with chlorine gas. The equation is shown. 2FeCl 2(aq) + Cl 2(g) 2FeCl 3(aq) Which statements about this reaction are correct? 1 Fe2+ ions are reduced to Fe3+ ions. 2 Chlorine acts as a reducing agent. 3 Fe2+ ions each lose an electron. 4 Cl 2 molecules are reduced to Cl – ions. A 1 and 2 B 2 and 3 C 2 and 4 D 3 and 4
Mark scheme: D
Q17 · Which statements about acids and bases are correct?
17 Which statements about acids and bases are correct? 1 An acid reacts with a metal to give off hydrogen. 2 A base reacts with an ammonium salt to give off ammonia. 3 An acid reacts with a carbonate to give off carbon dioxide. 4 Alkaline solutions are orange in methyl orange. A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4
Mark scheme: A
More questions on The characteristic properties of acids and bases
Q18 · Oxide 1 is a solid that reacts with dilute hydrochloric acid
18 Oxide 1 is a solid that reacts with dilute hydrochloric acid. Oxide 2 is a gas that reacts with sodium hydroxide solution. What are the formulae of the oxides? oxide 1 oxide 2 A CaO MgO B MgO NO2 C NO2 SO2 D SO2 CaO
Mark scheme: B
Q19 · Which reaction is a photochemical reaction?
19 Which reaction is a photochemical reaction? A addition of bromine to propene B esterification of ethanol and ethanoic acid C oxidation of ethanol D substitution of methane with chlorine
Mark scheme: D
Q20 · The equation shown represents a reaction at equilibrium
20 The equation shown represents a reaction at equilibrium. m and n represent the balancing numbers for the reactant and product respectively. mP(g) nQ(g) A high temperature increases the concentration of Q. A high pressure increases the concentration of Q. Which statement about the reaction is correct? A The forward reaction is exothermic and m is greater than n. B The forward reaction is exothermic and m is less than n. C The forward reaction is endothermic and m is greater than n. D The forward reaction is endothermic and m is less than n.
Mark scheme: C
Q21 · A period of the Periodic Table is shown
21 A period of the Periodic Table is shown. group I II III IV V VI VII VIII element R S T V W X Y Z The letters are not their chemical symbols. Which statement is correct? A Element R does not conduct electricity. B Elements R and Y react together to form an ionic compound. C Element Z exists as a diatomic molecule. D Element Z reacts with element T.
Mark scheme: B
Q22 · All metal nitrates are soluble in water
22 All metal nitrates are soluble in water. All metal chlorides are soluble except silver and lead. All metal carbonates are insoluble except sodium and potassium. Which aqueous solutions produce a precipitate when mixed together? 1 silver nitrate + sodium carbonate 2 silver nitrate + sodium chloride 3 barium nitrate + potassium chloride A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3
Mark scheme: A
Q23 · Which row describes properties of transition elements?
23 Which row describes properties of transition elements? property 1 property 2 property 3 A coloured compounds high density variable oxidation states B high density high melting point one oxidation state C high melting point coloured compounds one oxidation state D low melting point high density variable oxidation states
Mark scheme: A
Q24 · The noble gases are in Group VIII of the Periodic Table
24 The noble gases are in Group VIII of the Periodic Table. Which statement explains why noble gases are unreactive? A They all have eight electrons in their outer shells. B They all have full outer shells. C They are all gases. D They are all monoatomic.
Mark scheme: B
Q25 · Which statement is correct for all metals?
25 Which statement is correct for all metals? A They conduct electricity when molten. B They gain electrons when they form ions. C They have a low density. D They have a low melting point.
Mark scheme: A
Q26 · Carbon dioxide is produced during the extraction of aluminium from bauxite
26 Carbon dioxide is produced during the extraction of aluminium from bauxite. Which statement describes how this carbon dioxide is made? A Carbon monoxide reduces aluminium oxide forming carbon dioxide and aluminium. B Carbon is burned in the blast furnace to release heat energy. C Oxygen made in the process reacts with the carbon electrode. D The ore of aluminium undergoes thermal decomposition.
Mark scheme: C
Q27 · Aluminium objects do not need protection from corrosion
27 Aluminium objects do not need protection from corrosion. Iron objects must be protected from corrosion. Which statement explains why aluminium resists corrosion? A Aluminium does not form ions easily. B Aluminium does not react with water or air. C Aluminium has a protective oxide layer. D Aluminium is below iron in the reactivity series.
Mark scheme: C
Q28 · Which statements explain why zinc is used to protect iron from rusting?
28 Which statements explain why zinc is used to protect iron from rusting? 1 Zinc is more reactive than iron. 2 Zinc is less reactive than iron. 3 Zinc can form alloys with iron. 4 Zinc acts as a sacrificial metal. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4
Mark scheme: B
Q29 · Which conditions are used in the Haber process?
29 Which conditions are used in the Haber process? temperature pressure / C / atmospheres A 100 10 B 450 10 C 450 200 D 1000 500
Mark scheme: C
Q30 · Which process does not produce a greenhouse gas?
30 Which process does not produce a greenhouse gas? A acid rain on limestone buildings B combustion of wood C digestion in cows D zinc reacting with sulfuric acid
Mark scheme: D
Q31 · Which reaction involving sulfur dioxide is correct?
31 Which reaction involving sulfur dioxide is correct? A It is produced during the extraction of zinc from zinc blende. B It reacts with concentrated sulfuric acid to form oleum. C It reacts with sulfur to form sulfur trioxide. D It turns an acidified solution of potassium manganate(VII) purple.
Mark scheme: A
Q32 · Lime (calcium oxide) is used to treat waste water from a factory
32 Lime (calcium oxide) is used to treat waste water from a factory. Which substance is removed by the lime? A ammonia B sodium chloride C sodium hydroxide D sulfuric acid
Mark scheme: D
More questions on The characteristic properties of acids and bases
Q33 · What is the structure of the ester formed from ethanoic acid and propanol?
33 What is the structure of the ester formed from ethanoic acid and propanol? A B H H O H H O H C C C H H H C C C H H H O C C H H H C H H H H C H O H C D H O H O H C C H C C H H H H H C H O C C C H H H C H H H H H C H O H
Mark scheme: D
Q34 · Fuel X produces carbon dioxide and water when it is burned in air
34 Fuel X produces carbon dioxide and water when it is burned in air. So does fuel Y. What could X and Y be? X Y A C H2 B C C8H18 C CH4 H2 D CH4 C8H18
Mark scheme: D
Q35 · The structures of four organic molecules are shown
35 The structures of four organic molecules are shown. H H O H H O H C Cl H C O H H C C O H H C H H H H H How many different homologous series are represented by these molecules? A 1 B 2 C 3 D 4
Mark scheme: C
More questions on Formulae, functional groups and terminology
Q36 · Which statement about ethene is correct?
36 Which statement about ethene is correct? A It has the chemical formula C2H6. B It burns in excess oxygen producing carbon dioxide and water. C It reacts with Br2 to produce an orange solution. D It reacts with oxygen to form ethanol.
Mark scheme: B
Q37 · Ethanol is manufactured by fermentation of sugars or by catalytic hydration of ethene
37 Ethanol is manufactured by fermentation of sugars or by catalytic hydration of ethene. Which row states an advantage of each method? fermentation hydration A produces purer ethanol is a batch process B produces purer ethanol is a continuous process C uses a renewable resource is a batch process D uses a renewable resource is a continuous process
Mark scheme: D
Q38 · Which statements about unsaturated hydrocarbons are correct?
38 Which statements about unsaturated hydrocarbons are correct? 1 They contain both single and double bonds. 2 They turn aqueous bromine from colourless to brown. 3 They can be manufactured by cracking. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3
Mark scheme: B
Q39 · Which polymers have the same linkage between monomer units?
39 Which polymers have the same linkage between monomer units? A carbohydrate and polyamide B carbohydrate and polyester C protein and polyamide D protein and polyester
Mark scheme: C
Q40 · The diagram shows the partial structure of Terylene
40 The diagram shows the partial structure of Terylene. O O O C O O C C O From which pair of compounds is it made? O O A HO C C OH + HO OH O O B HO C OH + HO C OH O O C HO OH + HO C C OH O O O O D HO C C OH + HO C C OH
Mark scheme: A
What was in this paper
The subtopics covered by these 40 questions, and how many questions each got. Open one in a new tab to see every Cambridge question on it.
2Corrosion of metals2Electrolysis2Extraction of metals2Fuels2Giant covalent structures2Polymers2Redox2Reversible reactions and equilibrium2The characteristic properties of acids and bases2Air quality and climate1Alcohols1Alkanes1Alloys and their properties1Arrangement of elements1Carboxylic acids1Diffusion1Exothermic and endothermic reactions1Experimental design1Formulae, functional groups and terminology1Identification of ions and gases1Isotopes1Noble gases1Oxides1Preparation of salts1Properties of metals1Separation and purification1Simple molecules and covalent bonds1The mole and the Avogadro constant1Transition elements1What you needed in this session
Cambridge’s own grade thresholds for 2021 Oct/Nov, Paper 2 · Variant 2. A higher threshold means an easier paper — the bar moves with how the cohort did.