Chemistry 2024 · May/June

Which pair of formulae is correct? A Ag 2CO3 and (NH4)3NO3B K 2HCO3 and Zn3(PO4)2 C AgHCO 3 and K3PO4 D ZnCO 3 and (NH4)2PO4

How many molecules are present in 62 g of solid white phosphorus, P4? A L B 2L C

The first eight successive ionisation energies for two elements of Period 3 of the Periodic Table are shown in the graphs. 012345678 electron removed ionisation energy 012345678 electron removed ionisation energy What is the formula of the ionic compound formed from these elements? A MgCl 2 B CaBr 2 C Na 2S D K 2Se

In which pairs are both species free radicals? 1 Cl and O 2 Cl and O 3 Cl and O 4 Cl and O A 1, 3 and 4 B 1 and 3 only C 1 only D 2 only

Which shape is correctly predicted by VSEPR theory? number of bonded electron pairs number of lone pairs shape A 2 2 linear B 2 2 tetrahedral C 3 1 pyramidal D 3 1 trigonal planar

In which species does the underlined atom have an incomplete outer shell? A BF 3 B CH 3 - C F 2O D H 3O

In this question it should be assumed that nitrogen behaves as an ideal gas under the conditions stated. Which volume is occupied by 1.00 A 0.124 B 0.799 dm C 1.60 dm D 22.4 dm

Consider the following four compounds. 1 (CH 3)3CH 2 CH 3CH2CH2OH 3 CH 3CH2CH2SH 4 CH 3CH2CH2CH3 What is the order of increasing boiling point of the compounds (lowest first)?

Ethane can react with fluorine to produce 1,2-difluoroethane, C 2H4F2. bond energy kJ mol C-H 410 C-C 350 F-F 158 H-F 562 What is the bond energy of the C-F bond in 1,2-difluoroethane? A 407 kJ mol B 474 kJ mol C 486 kJ mol D 972 kJ mol

Which equation has an enthalpy change equal to the standard en thalpy of formation of sodium oxide? A Na

+ Na2O

+ O C 2Na

+ D 4Na

Nitrogen dioxide reacts with water. 2NO Which statement about this reaction is correct? A Both products are formed because oxygen atoms gain electrons. B Nitrogen atoms undergo disproportionation. C The oxidation number of hydrogen is increased. D Water acts as an oxidising agent.

Phosphorus reacts with concentrated sulfuric acid to produce phosphoric acid, sulfur dioxide and water. a, b, c, d and e are all whole numbers. The equation can be balanced by using oxidation numbers. What is the value of the sum a + b + c + d + e? A 10 B 14 C 15 D 16

The volume of ammonia produced against time is measured in two experiments. 2

+ 3H2

In experiment 1, 3 atm. A graph showing the volume of ammonia produced against time is plotted. Experiment 2 is then performed. Experiment 2 differs from experiment 1 in one condition only. volume of NH time experiment 1 experiment 2 How does experiment 2 differ from experiment 1? A An iron catalyst is present in experiment 2.B 2 mol of helium gas is present in the reaction mixture in experiment 2. C A pressure of 250 atm is used in experiment 2. D A temperature of 600

Which reaction has an equilibrium constant, K p, that has no units?A H 2

+ I 2

B 3H 2

C 2NO 2

D 2SO 2

Gas Q decomposes slowly at room temperature. The Boltzmann distribution curve for gas Q at room temperature is shown. energy number of particles Which change occurs when a catalyst is added to gas Q? A The peak of the curve moves to the right on the diagram. B The number of particles with enough energy to decompose increases. C The kinetic energy of the unreacted particles increases. D The value of E a decreases, moving the vertical dotted line to the right on the diagram.

Which statement is correct? A Aluminium chloride has a giant ionic lattice of Al and Cl ions. B Sodium chloride dissolves in water, forming hydrogen chloride and sodium hydroxide. C The strong covalent bonds in silicon chloride prevent it from reacting with water. D When phosphorus( V) chloride is added to water, the resulting solution conducts electricity.

A mixture of calcium carbonate, calcium nitrate, strontium carbonate and strontium nitrate is thermally decomposed. The decomposition reaction of each substance goes to completion. Each substance is anhydrous. How many different products are formed? A 4 B 5 C 7 D 8

W is a solid that reacts with water to produce an alkaline solution. The addition of two drops of dilute H 2SO4 to this alkaline solution produces a white precipitate. What could be the identity of solid W? A magnesium hydroxide B magnesium oxide C barium oxide D phosphorus oxide

Chlorine gas is reacted with cold aqueous sodium hydroxide. Which statement is correct for this reaction? A Chlorine is both oxidised and reduced. B Chlorine is neither oxidised nor reduced. C Chlorine is oxidised but not reduced. D Chlorine is reduced but not oxidised.

Sodium is added to water to form solution Y. The pH of solution Y is measured. When powdered substance X is added to solution Y, the pH falls. Which two compounds could each be substance X? A MgCl 2 and Al (OH)3 B MgCl 2 and K2O C NaCl and Al

3 D NaCl and K

The table shows statements about some of the properties of halogens and their compounds and explanations for these properties. Which row shows a correct statement about the property and a correct explanation for the statement? statement explanation A iodine is a solid at room temperature the I-I bond strength is high the decomposition of hydrogen iodide is more endothermic than the decomposition of hydrogen chloride chlorine is more reactive than iodine when chlorine is bubbled into aqueous potassium iodide, a purple solution is seen chlorine is a stronger oxidising agent than iodine when concentrated sulfuric acid is added to solid potassium iodide, a purple vapour is seen iodide ions are being oxidised to iodine by the sulfuric acid

Which statement describes a property of an ammonium ion? A An aqueous ammonium ion is a weak Brønsted-Lowry base. B Aqueous ammonium sulfate reacts with dilute hydrochloric acid to make ammonia gas. D The four N-H covalent bonds in an ammonium ion are identical to each other.

Catalytic converters are fitted in the exhaust systems of many cars. Gas X: What is gas X? A carbon dioxide B carbon monoxide C hydrocarbon vapour D nitrogen dioxide

In the general formula of which class of compound is the ratio of hydrogen atoms to carbon atoms the highest? A alcohols B aldehydes C carboxylic acids D halogenoalkanes

Which statement is correct? A Adding sodium oxide to water gives a lower pH solution than adding silicon oxide to water. B The oxidation state of sodium in its chloride is higher than the oxidation state of silicon in its chloride. C The atomic radius of sodium is larger than that of silicon. D The melting point of the chloride of sodium is lower than the melting point of the chloride of silicon. g cm under room conditions. Z reacts with an excess of hot concentrated acidified KMnO 4. Only one type of carboxylic acid is formed in this reaction. What is Z? A but-2-ene B 2,3-dimethylbut-2-ene C hex-2-ene D hex-3-ene

Compound X can be oxidised to compound Y. Compound Y gives a yellow precipitate with alkaline I 2(aq). What is compound X? A butan-1-ol B butan-2-ol C methylpropan-1-ol D methylpropan-2-ol

Aqueous NaOH reacts with 1-bromopropane to give propan-1-ol. What should be included in a diagram of the first step in the mechanism? A a curly arrow from a lone pair on the OH ion to the C atom of 1-bromopropane B a curly arrow from the C atom of 1-bromopropane to the OHion C a curly arrow from the C-Br bond to the C atom D the homolytic fission of the C-Br bond

In which reaction is the organic compound oxidised? A CH 3CH2CH2CHO + Tollens' reagent B CH 3CH2CH2CHO + LiAl H4 C CH 3CH2CH2OH + concentrated H3PO4 D CH 3CO2C2H5 + dilute H2SO4

1 mole of each of the following four compounds is reacted separately with: Which compound produces the same volume of gas with each of the two reagents? HO HO

Which reaction will distinguish between propan-1-ol and propan-2-ol? A warming with acidified KMnO B warming with acidified K 2Cr2O7 C dehydration, followed by reaction with Br 2(aq) D mild oxidation, followed by reaction with Fehling's reagent

Compound T has the skeletal formula shown. compound T Which structure is a structural isomer of compound T? A B CD

The diagram shows a simplified structure of coenzyme Q 10. coenzyme Q Which row describes the structure of coenzyme Q 10 correctly? the coenzyme is in one molecule A an aldehyde n + 2 B an aldehyde n + 4 C a ketone n + 2 D a ketone n + 4

The molecule of limonene, C 10H16, contains a 6-membered ring. This is the only cyclic component in its structure. Which volume of hydrogen, at room conditions, is required to react completely with the C=C double bonds in one mole of limonene? A 12 B 24 dm C 48 dm D 72 dm

1-bromopropane reacts with hot ethanolic NaOH. What is the molecular formula of the product in this reaction?A C 3H6 B C 3H8 C C 3H7O D C 3H8O

A sample of pent-2-en-4-ol, C 5H10O, contains all the possible stereoisomers of this compound. How many stereoisomers are there in the sample? A 2 B 3 C 4 D 5

Which pair of reagents reacts to form a product with a chiral carbon atom? A CH 3CH=CH2 + HBr B (CH 3)2C=O + NaBH4 C CH 3CH2CHO + HCN D CH 3COOH + CH3CH2OH

The diagrams show the structures of two esters, X and Y, that are formed in ripening apples. ester Yester X Which carboxylic acids are formed when these esters are hydrolysed by H 2SO4(aq)? ester X ester Y A CH 3COOH CH 3CH2COOH B CH 3COOH CH 3CH2CH(CH3)COOH C CH 3CH(CH3)CH2COOH CH 3CH2COOH D CH 3CH(CH3)CH2COOH CH 3CH2CH(CH3)COOH

An addition polymer is made from monomer Z. CH C monomer ZOCH What is the structure of the polymer made from this monomer? CH CH C CH CH C O CH COCHOCH

Compound X reacts with acidified K2Cr2O7 to form compound Y. The infrared spectrum of compound Y is shown. transmittance 4000 3000 2000 wavenumber / cm 1500 1000 500 bond functional groups containing the bond characteristic infrared absorption range (in wavenumbers) / cm C-O hydroxy, ester 1040-1300 C=O amide carbonyl, carboxyl ester C=C aromatic compound, alkene 1500-1680 C-H alkane 2850-2950 O-H carboxyl hydroxy N-H amine, amide 3300-3500 What is the identity of compound X? A propan-1-ol B propan-2-ol C propanone D propanoic acid 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. Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. Important values, constants and standards molar gas constant R = 8.31J Kmol C molmol-19 molar volume of gas V m = 22.4 dmmol at s.t.p. (101 kPa and 273 K) m = 24.0 dmmol at room conditions ionic product of water K-14mol specific heat capacity of water c = 4.18 kJ kg (4.18 J g Group The Periodic Table of Elements hydrogen 1.0 He helium 4.0 1213 14 15 16 17 18 3 4 5 6 7 8 9 10 11 123Li lithium 6.9 beryllium 9.0 atomic number atomic symbolKey name relative atomic mass sodium 23.0 magnesium 24.3 potassium 39.1 calcium 40.1 rubidium 85.5 strontium 87.6 caesium 132.9 barium 137.3 francium Ra radium boron 10.8 13 Al aluminium 27.0 31 Ga gallium 69.7 49 In indium 114.8 thallium 204.4 carbon 12.0 14 Si silicon 28.1 32 Ge germanium 72.6 50 Sntin 118.7 82 Pb lead 207.2 titanium 47.9 40 Zr zirconium 91.2 72 Hf hafnium 178.5 rutherfordium vanadium 50.9 41 Nb niobium 92.9 73 Ta tantalum 180.9 105 Db dubnium chromium 52.0 42 Mo molybdenum 95.9 74 W tungsten 183.8 106 Sg seaborgium manganese 54.9 43 Tc technetium rhenium 186.2 107 Bh bohrium iron 55.8 44 Ru ruthenium 101.1 76 Os osmium 190.2 108 Hs hassium Co cobalt 58.9 45 Rh rhodium 102.9 iridium 192.2 109 Mt meitnerium nickel 58.7 46 Pd palladium 106.4 platinum 195.1 11 0 Ds darmstadtium copper 63.5 47 Ag silver 107.9 79 Au gold 197.0 111 Rg roentgenium zinc 65.4 48 Cd cadmium 112.4 80 Hg mercury 200.6 11 2 Cn copernicium 11 4 flerovium 11 6 livermorium nitrogen 14.0 phosphorus 31.0 33 As arsenic 74.9 51 Sb antimony 121.8 bismuth 209.0 oxygen 16.0 sulfur 32.1 34 Se selenium 79.0 52 Te tellurium 127.6 84 Po polonium fluorine 19.0 17 Cl chlorine 35.5 35 Br bromine 79.9 iodine 126.9 Ne neon 20.2 18 Ar argon 39.9 36 Kr krypton 83.8 54 Xe xenon 131.3 86 Rn radon 11 3 nihonium 11 5 moscovium 11 7 tennessine 11 8 oganesson scandium 45.0 yttrium 88.9 57-71 lanthanoids 89-103 actinoids 57La lanthanum 138.9 89 Ac lanthanoids actinoids actinium Ce cerium 140.1 90 Th thorium 232.0 praseodymium 140.9 91 Pa protactinium 231.0 neodymium 144.4 uranium 238.0 promethium neptunium samarium 150.4 94 Pu plutonium europium 152.0 95 Am americium gadolinium 157.3 96 Cm curium terbium 158.9 97 Bk berkelium dysprosium 162.5 californium holmium 164.9 99 Es einsteinium erbium 167.3 100 Fm fermium Tm thulium 168.9 101 Md mendelevium ytterbium 173.1 102 No nobelium lutetium 175.0 lawrencium