Cambridge IGCSE Chemistry (9-1) 0971 — 2023 Oct/Nov Paper 2 · Variant 2

Question 1

1. Part of a cooling curve for water is shown.

100

temperature /°C

time/min

What is occurring between points X and Y?

A Steam is condensing into water.

B- The temperature of the water is decreasing.
C Ice is melting.
D

Particles are losing heat to the surroundings.

Accepted Answer

D

Question 2

2 Which statements about clean, dry air are correct? 1 It is a mixture of elements only. 2 It is a mixture of elements and compounds. 3 It contains only non-metals. A 1 and 3 B 1 only C 2 and 3 D 2 only

Accepted Answer

C

Question 3

3 A representation of an atom is shown. – + + – – + + – – + + – What is the nucleon number of this atom? A 6 B 7 C 12 D 13

Accepted Answer

D

Question 4

4 The percentage abundances of three isotopes in a sample of neon are shown. percentage isotope abundance / % 20 Ne 90.48 10 21 Ne 0.27 10 22 Ne 9.25 10 What is the relative atomic mass, Ar, of this sample of neon? A 10.19 B 20.19 C 21.00 D 30.19

Accepted Answer

B

Question 5

5 Potassium reacts with iodine to form potassium iodide. Which statement about potassium iodide is correct? A Each potassium atom shares a pair of electrons with an iodine atom. B In potassium iodide, the particles of potassium have more protons than electrons. C Potassium iodide has a high melting point because it is a covalent compound. D Potassium iodide has a low melting point because it is an ionic compound.

Accepted Answer

B

Question 6

6 Which substance has the lowest melting point? A graphite B methanol C silicon(IV) oxide D sodium chloride

Accepted Answer

B

Question 7

7 The diagram shows the structure of a molecule of ethyl ethanoate. H O H C C H H H O C C H H H What is the molecular formula of a molecule of ethyl ethanoate? A CHO B C4H8O2 C C4(H2)2(O2) D C2H4O

Accepted Answer

B

Question 8

8 A hydrocarbon contains 85.7% of carbon by mass. What is the empirical formula of the hydrocarbon? A CH2 B CH4 C C2H5 D C3H6

Accepted Answer

A

Question 9

9 The formula of a compound containing element X is Na2X2O3. The relative formula mass of the compound is 158. What is the relative atomic mass of X? A 32 B 59.5 C 64 D 119

Accepted Answer

A

Question 10

10 Dilute aqueous potassium chloride is electrolysed using platinum electrodes. Which row identifies the product at each electrode? anode cathode A chlorine hydrogen B chlorine potassium C oxygen hydrogen D oxygen potassium

Accepted Answer

C

Question 11

11 Concentrated aqueous copper(II) chloride is electrolysed using copper electrodes, as shown. power supply + – copper electrodes aqueous copper(II) chloride What happens to the mass of each electrode during this process? positive electrode negative electrode A decreases decreases B decreases increases C increases decreases D increases increases

Accepted Answer

B

Question 12

12 The initial and final temperatures of four different reactions are measured. Which reaction is the least exothermic? initial final temperature temperature / C / C A 19 25 B 21 18 C 22 17 D 22 26

Accepted Answer

D

Question 13

13 Which equation represents an endothermic reaction? A Cl 2(g)    2Cl (g) B CH4(g)  +  2O2(g)    CO2(g)  +  2H2O(l) C H(g)  +  H(g)    H2(g) D 2K(s)  +  2H2O(l)    2KOH(aq)  +  H2(g)

Accepted Answer

A

Question 14

14 Methane burns in oxygen to form carbon dioxide and water. CH4(g)  +  2O2(g)    CO2(g)  +  2H2O(l) The bond energies are shown. bond energy bond in kJ / mol C–H 410 C–O 360 C=O 805 O–H 460 O–O 146 O=O 496 What is the energy change for this reaction? A –818 kJ / mol B –102 kJ / mol C +102 kJ / mol D +818 kJ / mol

Accepted Answer

A

Question 15

15 Hydrochloric acid is added to excess calcium carbonate in two separate experiments. Two different concentrations of hydrochloric acid are used but the temperature is the same in both experiments. The graph of the results shows the volume of carbon dioxide gas given off over time. 2.0 mol / dm3 volume of carbon dioxide given off 1.0 mol / dm3 time Which row is correct? particles in 2.0 mol / dm3 compared to 1.0 mol / dm3 collision rate collision energy A higher no change B higher higher C lower no change D lower higher

Accepted Answer

A

Question 16

16 The decomposition of dinitrogen tetroxide, N2O4, into nitrogen dioxide, NO2, is a reversible reaction. The equation for the reaction is shown. N2O4(g) 2NO2(g) The forward reaction is endothermic. Which row shows the effect on the position of equilibrium and the rate of the reverse reaction when the temperature is increased? position of rate of the equilibrium reverse reaction A shifts to the left decreases B shifts to the left increases C shifts to the right decreases D shifts to the right increases

Accepted Answer

D

Question 17

17 In a blast furnace, iron(III) oxide is converted to iron and carbon monoxide is converted to carbon dioxide. Fe2O3  +  3CO    2Fe  +  3CO2 What happens to each of these reactants? A Both iron(III) oxide and carbon monoxide are oxidised. B Both iron(III) oxide and carbon monoxide are reduced. C Iron(III) oxide is oxidised and carbon monoxide is reduced. D Iron(III) oxide is reduced and carbon monoxide is oxidised.

Accepted Answer

D

Question 18

18 Which row describes what happens to Fe2+ ions when they are oxidised? oxidation number electron movement of iron A they gain electrons decreases B they gain electrons increases C they lose electrons decreases D they lose electrons increases

Accepted Answer

D

Question 19

19 In which reaction does an acid react with a base? A Dilute sulfuric acid is added to a piece of magnesium ribbon producing hydrogen. B Dilute sulfuric acid is added to aqueous barium chloride producing a white precipitate of barium sulfate. C Aqueous sodium hydroxide is added to aqueous copper(II) sulfate producing a blue precipitate of copper(II) hydroxide. D Aqueous sodium hydroxide is added to solid ammonium sulfate producing gaseous ammonia.

Accepted Answer

D

Question 20

20 Which element forms an oxide that reacts with an aqueous solution of a base? A argon B sulfur C magnesium D copper

Accepted Answer

B

Question 21

21 Which method is used to produce insoluble salts? A addition of excess insoluble base to an acid B addition of excess metal to an acid C precipitation using two aqueous solutions D titration using an acid and an alkali

Accepted Answer

C

Question 22

22 The noble gases are in Group VIII of the Periodic Table. Some properties of the first four noble gases are shown. boiling point density noble gas in g / dm3 in C helium –267 0.179 neon –246 0.900 argon –186 1.782 krypton –152 3.708 Which row identifies the trends in boiling point and in density as Group VIII is descended? boiling point density A decreasing increasing B increasing increasing C decreasing decreasing D increasing decreasing

Accepted Answer

B

Question 23

23 Some properties of element R are shown. melting point in C 98 boiling point in C 883 reaction with cold water gives off H2 gas reaction when heated with oxygen burns to give a white solid In which part of the Periodic Table is R found? A Group I B Group VII C Group VIII D transition elements

Accepted Answer

A

Question 24

24 Which pair of compounds shows that transition elements have variable oxidation states? A Cr2O3 and CrBr3 B CuSO4 and CuCl 2 C Fe2O3 and FeCl 2 D NiO and NiCl 2

Accepted Answer

C

Question 25

25 The list gives the order of some metals and hydrogen in the reactivity series. Metal X is also included. most reactive K Mg Zn H X least reactive Cu Which row shows the properties of metal X? reacts with oxide reduced dilute acids by carbon A no no B no yes C yes no D yes yes

Accepted Answer

B

Question 26

26 When zinc is added to an aqueous solution containing magnesium ions, there is no reaction. Which species has the greatest tendency to lose electrons? A Mg B Mg2+ C Zn D Zn2+

Accepted Answer

A

Question 27

27 Which gas in the air is needed for iron to rust? A argon B carbon dioxide C nitrogen D oxygen

Accepted Answer

D

Question 28

28 Which coating prevents iron from rusting even when the coating is damaged? A grease B paint C plastic D zinc

Accepted Answer

D

Question 29

29 Why is limestone added to the blast furnace? A It neutralises the molten slag produced. B It reacts with impurities to form slag. C It releases carbon dioxide which reduces the iron(III) oxide. D It removes acidic gases such as carbon dioxide.

Accepted Answer

B

Question 30

30 The flow chart shows stages in the treatment of river water to produce drinking water. river sedimentation stage stage drinking water tank J K water What occurs at stages J and K? J K A distillation chlorination B distillation filtration C filtration chlorination D filtration distillation

Accepted Answer

C

Question 31

31 Carbon dioxide acts as a greenhouse gas by interacting with a particular type of energy that radiates from the Earth’s surface into the atmosphere. Which type of energy is involved and what happens when this energy interacts with carbon dioxide molecules? type of what happens energy involved A thermal carbon dioxide molecules increase the Earth’s energy loss to space B thermal carbon dioxide molecules absorb the energy C light carbon dioxide molecules increase the Earth’s energy loss to space D light carbon dioxide molecules absorb the energy

Accepted Answer

B

Question 32

32 Oxides of nitrogen, such as NO and NO2, are formed in the petrol engines of cars. They are removed from the exhaust gases by reactions in the car’s catalytic converter. Which row describes how oxides of nitrogen are formed in a petrol engine and a reaction that happens in the catalytic converter? a reaction that happens how oxides of nitrogen are formed in the catalytic converter A by the reaction between 2NO  +  2CO    N2  +  2CO2 nitrogen and oxygen from the air B by the reaction between 2NO  +  2H2    N2  +  2H2O nitrogen and oxygen from the air C by the reaction between nitrogen 2NO  +  2CO    N2  +  2CO2 compounds in petrol and oxygen from the air D by the reaction between nitrogen 2NO  +  2H2    N2  +  2H2O compounds in petrol and oxygen from the air

Accepted Answer

A

Question 33

33 Which diagram shows the displayed formula for the named organic compound? A B C D H O H H H O H H H H C C O O H H C C H H C C H H C C H H H H H H H H ethanoic acid ethene ethanol methane

Accepted Answer

C

Question 34

34 What is the total number of covalent bonds in a molecule of butane, C4H10? A 3 B 10 C 13 D 14

Accepted Answer

C

Question 35

35 Propane reacts with chlorine in a substitution reaction. Which reaction condition is required for the reaction to occur? A acid catalyst B iron catalyst C temperature of 400 C D ultraviolet light

Accepted Answer

D

Question 36

36 The structure of an organic compound is shown. H H H H C C C O H H H H Which structure represents a molecule that reacts with steam to produce this product? A B C D H H H H H H H H H H C C H C C C H H C C O H H C C C H H H H H H H H H

Accepted Answer

D

Question 37

37 Which term describes nylon? A addition polymer B natural polymer C polyamide D polyester

Accepted Answer

C

Question 38

38 Ethene can be polymerised. Which diagram represents the structure of the product formed? A B C D H H H H H H H H H H C C C C C C H C C C C H H H H H H H H H H H n n

Accepted Answer

C

Question 39

39 An acid–base titration is described. ● 25.0 cm3 of dilute aqueous alkali is put into a conical flask. ● Indicator is added to the flask. ● Dilute acid is added to the aqueous alkali until the indicator changes colour. ● The volume of acid used is then recorded. Which use of apparatus is correct? A The 25.0 cm3 of aqueous alkali is measured using a volumetric pipette. B The 25.0 cm3 of aqueous alkali is measured using the lines on the conical flask. C The volume of acid is measured using a measuring cylinder. D The volume of acid is measured using a volumetric pipette.

Accepted Answer

A

Question 40

40 Substance Q is investigated using chromatography. The chromatogram is shown. The diagram is not drawn to scale. solvent front Q 129 mm 114 mm 83 mm baseline 13 mm Q What is the Rf value of Q? A 0.60 B 0.64 C 0.69 D 0.72

Accepted Answer

C

Question paper16 pages

Mark scheme3 pages

Questions as text

Q1 · Part of a cooling curve for water is shown

Q2 · Which statements about clean, dry air are correct?

Q3 · A representation of an atom is shown

Q4 · The percentage abundances of three isotopes in a sample of neon are shown

Q5 · Potassium reacts with iodine to form potassium iodide

Q6 · Which substance has the lowest melting point?

Q7 · The diagram shows the structure of a molecule of ethyl ethanoate

Q8 · A hydrocarbon contains 85.7% of carbon by mass

Q9 · The formula of a compound containing element X is Na2X2O3

Q10 · Dilute aqueous potassium chloride is electrolysed using platinum electrodes

Q11 · Concentrated aqueous copper(II) chloride is electrolysed using copper electrodes, as shown

Q12 · The initial and final temperatures of four different reactions are measured

Q13 · Which equation represents an endothermic reaction?

Q14 · Methane burns in oxygen to form carbon dioxide and water

Q15 · Hydrochloric acid is added to excess calcium carbonate in two separate experiments

Q16 · The decomposition of dinitrogen tetroxide, N2O4, into nitrogen dioxide, NO2, is a…

Q17 · In a blast furnace, iron(III) oxide is converted to iron and carbon monoxide is converted…

Q18 · Which row describes what happens to Fe2+ ions when they are oxidised?

Q19 · In which reaction does an acid react with a base?

Q20 · Which element forms an oxide that reacts with an aqueous solution of a base?

Q21 · Which method is used to produce insoluble salts?

Q22 · The noble gases are in Group VIII of the Periodic Table

Q23 · Some properties of element R are shown

Q24 · Which pair of compounds shows that transition elements have variable oxidation states?

Q25 · The list gives the order of some metals and hydrogen in the reactivity series

Q26 · When zinc is added to an aqueous solution containing magnesium ions, there is no reaction

Q27 · Which gas in the air is needed for iron to rust?

Q28 · Which coating prevents iron from rusting even when the coating is damaged?

Q29 · Why is limestone added to the blast furnace?

Q30 · The flow chart shows stages in the treatment of river water to produce drinking water

Q31 · Carbon dioxide acts as a greenhouse gas by interacting with a particular type of energy…

Q32 · Oxides of nitrogen, such as NO and NO2, are formed in the petrol engines of cars

Q33 · Which diagram shows the displayed formula for the named organic compound?

Q34 · What is the total number of covalent bonds in a molecule of butane, C4H10?

Q35 · Propane reacts with chlorine in a substitution reaction

Q36 · The structure of an organic compound is shown

Q37 · Which term describes nylon?

Q38 · Ethene can be polymerised

Q39 · An acid–base titration is described

Q40 · Substance Q is investigated using chromatography

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