Chemistry 9701/13 October/November 2023: question paper and mark scheme

Question

Sodium azide, NaN3 is an explosive used to inflate airbags in cars when they crash. It consists of positive sodium ions and negative azide ions. What are the numbers of electrons in the sodium ion and the azide ion? sodium ion azide ion A 10 20 B 10 22 C 12 20 D 12 22

Question

The graph shows the variation of the first ionisation energy with proton number for some elements. The letters used are not the actual symbols for the elements. P X first ionisation W energy / kJ mol–1 U V R T S Q proton number Which statement about the elements is correct? A P and X are in the same period in the Periodic Table. B The general increase from Q to X is due to increasing atomic radius. C The small decrease from R to S is due to decreased shielding. D The small decrease from U to V is due to repulsion between paired electrons.

Question

Aluminium carbide, Al 4C3, reacts readily with aqueous sodium hydroxide. The two products of the reaction are NaAl O2 and a hydrocarbon. Water molecules are also involved as reactants. What is the formula of the hydrocarbon? A CH4 B C2H6 C C3H8 D C6H12

Question

A sample of 35.6 g of hydrated sodium carbonate contains 25.84% sodium ions by mass. When this sample is heated, anhydrous sodium carbonate and water are formed. Which mass of water is given off? A 7.2 g B 10.6 g C 14.4 g D 21.2 g

Question

Solid aluminium chloride sublimes at 178 °C. Which structure best represents the species in the vapour at this temperature? A B C D Cl Cl Cl Cl Cl Cl Cl Cl Al 3+(Cl –)3 Al Al Al Al Al Cl Cl Cl Cl Cl Cl Cl

Question

Which row is correct? + shape of H3O shape of SCl 2 A pyramidal non-linear B pyramidal linear C trigonal planar non-linear D trigonal planar linear 3

Question

When an evacuated tube of volume 400 cm is filled with gas at 300 K and 101 kPa, the mass of the tube increases by 0.65 g. Assume the gas behaves as an ideal gas. What is the identity of the gas? A argon B helium C krypton D neon

Question

Nitrogen, N2, and carbon monoxide, CO, both have Mr = 28. The boiling point of N2 is 77 K. The boiling point of CO is 82 K. What could be responsible for this difference in boiling points? A CO molecules have a permanent dipole; the N2 molecules are not polar. B N2 has and bonding; CO has bonding only. C N2 has a strong N≡N bond; CO has a C=O bond. D The CO molecule has more electrons than the N2 molecule.

Question

Which statement about enthalpy changes is correct? A Enthalpy changes of reaction are always negative. B Enthalpy changes of combustion are always positive. C Enthalpy changes of formation are always positive. D Enthalpy changes of neutralisation are always negative.

Question

What is the definition of standard enthalpy change of neutralisation, ? A when one mole of an aqueous acid is neutralised by an aqueous alkali B when one mole of an aqueous alkali is neutralised by an aqueous acid C when one mole of an aqueous acid is neutralised by one mole of an aqueous alkali D when an aqueous acid and an aqueous alkali react together to produce one mole of water

Question

HOCl (aq) is the molecule that kills bacteria when chlorine is added to water. The following reaction produces this molecule. + – Cl 2(g) + H2O(I) HOCl (aq) + H (aq) + Cl (aq) Which statement about this reaction is correct? A Chlorine is both oxidised and reduced. B Chlorine is oxidised but not reduced. C Hydrogen is both oxidised and reduced. D Hydrogen is oxidised but not reduced.

Question

Nitrogen dioxide, NO2, exists in equilibrium with dinitrogen tetroxide, N2O4. –1 2NO2(g) N2O4(g) H = –57 kJ mol Which conditions give the greatest percentage of N2O4(g) at equilibrium? pressure temperature A high high B high low C low high D low low

Question

When an equimolar mixture of H2 and I2 react, the mole fraction of HI in the final mixture is x. What is the equilibrium constant, Kp, for the reaction? A B C D

Question

In reaction 1, a student measures the initial rate of production of CO2(g) when CuCO3(s) is added 3 −3 to 50 cm of 0.1 mol dm HNO3(aq). 3 −3 In reaction 2, the student repeats the experiment using 50 cm of 0.5 mol dm HNO3(aq) and the same mass of CuCO3(s). In reaction 1 and reaction 2, the acid is in excess and samples of the same CuCO3 powder are used. Which row is correct? A greater than 1 greater than 1 B greater than 1 less than 1 C less than 1 greater than 1 D less than 1 less than 1

Question

The forward reaction of a reversible reaction is exothermic and has an activation energy of –1 +30 kJ mol . The reverse reaction proceeds by a mechanism that is the exact reverse of the mechanism of the forward reaction. Which statement about the activation energy of the reverse reaction is correct? –1 A The activation energy for the reverse reaction is equal to –30 kJ mol . –1 B The activation energy for the reverse reaction is greater than 0 kJ mol but less than –1 +30 kJ mol . –1 C The activation energy for the reverse reaction is equal to +30 kJ mol . –1 D The activation energy for the reverse reaction is greater than +30 kJ mol .

Question

X, Y and Z are elements all found within Groups 13, 14 and 15 of the Periodic Table. X is in the same group in the Periodic Table as Y. Y and Z are in Period 3. The first ionisation energy of X is greater than the first ionisation energy of Y. The melting point of Z is less than the melting point of Y. Y and Z both form chlorides which are white solids. These white solids react with water to produce solutions with a pH of less than 4. Which row of the table shows the possible identities of X and Y? X Y A B Al B Ge Si C As P D N P

Question

Which row about silicon, Si, and magnesium, Mg, and their ions is correct? comparison of silicon explanation and magnesium A Si has a greater Si has electrons in 3p orbitals. atomic radius than Mg. Mg has electrons in the 3s orbital only. B Si has a lower electrical Si has 4 delocalised electrons per atom. conductivity than Mg. Mg only has 2 delocalised electrons per atom. C Si has a lower Si has covalent bonding. melting point than Mg. Mg has metallic bonding. 4+ D The radius of Si is smaller Si has a greater 2+ than the radius of Mg . nuclear charge than Mg.

Question

Bromocresol green is an acid-base indicator. Below a pH of 3.8 it is yellow. Above a pH of 5.4 it is blue. Between these values it is green. Bromocresol green is added to the aqueous solution formed when the chloride of element T is added to water. The colour becomes yellow. When an excess of the solid oxide of element U is slowly added to this yellow solution, the indicator turns green then blue. Which row could identify element T and element U? element T element U A silicon sodium B silicon phosphorus C magnesium sodium D magnesium phosphorus

Question

Which row correctly describes the separate reactions of calcium and strontium with water? substance reduced substance oxidised more vigorous reaction A calcium or strontium water calcium + water B calcium or strontium water strontium + water C water calcium or strontium calcium + water D water calcium or strontium strontium + water

Question

L and M are both compounds of Group 2 elements. L and M are both soluble in water. When solutions of L and M are mixed, a white precipitate is formed. What could be L and M? A barium chloride and magnesium sulfate B barium sulfate and magnesium chloride C barium nitrate and magnesium chloride D barium carbonate and magnesium nitrate

Question

A 5.00 g sample of an anhydrous Group 2 metal nitrate loses 3.29 g in mass when heated strongly. Which metal is present? A magnesium B calcium C strontium D barium

Question

In this question, Q represents an atom of chlorine, bromine or iodine. Which explanation for the variation in volatility down Group 17 is correct? A Instantaneous dipole–induced dipole forces between molecules become stronger. B Permanent dipole–permanent dipole forces between molecules become stronger. C The bond energy of the Q2 molecules decreases. + – D The first ionisation energy Q(g) → Q (g) + e decreases.

Question

Which statement about the halogens or halide ions is correct? A Bromide ions react to form a white precipitate when added to silver nitrate solution. B Bromine does not oxidise chloride ions when added to sodium chloride solution. C Fluorine atoms form cations by accepting electrons when they react. D Chloride ions are stronger reducing agents than iodide ions.

Question

If ammonium cyanate is heated in the absence of air, the only product of the reaction is urea, CO(NH2)2. No other products are formed in the reaction. What is the formula of the cyanate ion present in ammonium cyanate? – 2– – 2– A CON2 B CON2 C OCN D OCN

Question

Hexamine is a crystalline solid used as a fuel in portable stoves. The diagram shows its skeletal structure. hexamine N N N N What is the empirical formula of hexamine? A CH2N B C3H6N2 C C4H8N4 D C6H12N4

Question

The compound aspartame is widely used as a sweetener in ‘diet’ soft drinks. aspartame CH3 O O O HO C6 H 5 NH O NH2 Aspartame is chiral. (There are no chiral carbon atoms in C6H5.) How many chiral carbon atoms are present in a molecule of aspartame? A 1 B 2 C 3 D 4

Question

How many and bonds are in the molecule HCCCH2CH2CHC(CH3)2? A 17 3 B 17 5 C 18 4 D 19 3

Question

The hydrocarbon C17H36 can be cracked. Which compound is the least likely to be produced in this reaction? A C3H8 B C4H8 C C8H16 D C16H34

Question

Which compound has an Mr of 84 and will react with HBr to give a product with an Mr of 164.9? A B C D O 30 β-carotene is responsible for the orange colour of carrots. β-carotene CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 β-carotene is oxidised by hot, concentrated, acidified KMnO4. When an individual molecule of β-carotene is oxidised in this way, many product molecules are formed. How many of these product molecules contain a ketone functional group? A 4 B 6 C 9 D 11 31 1,1-dichloropropane reacts with aqueous sodium hydroxide in a series of steps to give propanal. NaOH(aq) CH3CH2CHCl 2 CH3CH2CHO Which term describes the first step of this reaction? A addition B elimination C oxidation D substitution

Question

In the question paper above.

Question

In the question paper above.

Question

Propanoic acid can be made from bromoethane using a two-stage synthesis. Which pair of reagents is most suitable? reagent for stage 1 reagent for stage 2 A hydrogen cyanide aqueous sodium hydroxide B aqueous sodium hydroxide excess acidified potassium dichromate(VI) C ethanolic sodium hydroxide acidified potassium manganate(VII) D potassium cyanide dilute hydrochloric acid

Question

Alcohol X gives a yellow precipitate with alkaline I2(aq). What is the structure of X? A B C D OH CH2OH OH OH −

Question

When ethanol reacts with sodium metal, ethoxide ions, CH3CH2O , are produced. − When water reacts with sodium metal, OH ions are produced. Which statement about these reactions and the ethoxide ion is correct? A At the same temperature, the rate of reaction between sodium and ethanol is greater than that between sodium and water. − − B CH3CH2O is a stronger base than OH due to the electron-donating effect of the ethyl group. C The negative charge on the oxygen in an ethoxide ion is delocalised. D It is easier to deprotonate ethanol as it is more acidic than water.

Question

Menthol is a naturally occurring alcohol. menthol OH When menthol is heated with concentrated sulfuric acid it reacts. The products formed include compound T. What is the structure of compound T? A B C D O

Question

Which compound will produce a yellow-orange precipitate when added to 2,4-dinitrophenylhydrazine? A B C D O O O OH O –

Question

Ethanal, CH3CHO, undergoes an addition reaction with HCN in the presence of CN ions. Which row identifies the type of reaction and the name of the product formed? type of reaction name of product A electrophilic addition 2-hydroxypropanenitrile B electrophilic addition 2-hydroxyethanenitrile C nucleophilic addition 2-hydroxypropanenitrile D nucleophilic addition 2-hydroxyethanenitrile

Question

The structure of compound X is shown. X O O What is produced when X is heated with NaOH(aq)? A B ONa OH HO HO O O C D O O HO HO ONa OH

Question

The infrared spectrum of compound L is shown. 100 transmittance % 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 bond functional groups containing the bond characteristic infrared absorption range (in wavenumbers) / cm–1 C–O hydroxy, ester 1040–1300 C=C aromatic compound, alkene 1500–1680 C=O amide 1640–1690 carbonyl, carboxyl 1670–1740 ester 1710–1750 C≡N nitrile 2200–2250 C–H alkane 2850–2950 N–H amine, amide 3300–3500 O–H carboxyl 2500–3000 hydroxy 3200–3600 What is the structure of L? A HOCH2COCH2OH B HOCH2CH(OH)CHO C HOCH2CH(OH)CH2OH D HOCH2CH2COOH

Question

In the mass spectrum of compound J, the ratio of the height of the M +1 ion peak to the height of the M + ion peak is 4 : 91. Compound J forms a carboxylic acid when heated with acidified K2Cr2O7. What is compound J? A butanal B butanone C propan-1-ol D propanenitrile Important values, constants and standards –1 –1 molar gas constant R = 8.31 J K mol 4 –1 Faraday constant F = 9.65 × 10 C mol 23 –1 Avogadro constant L = 6.022 × 10 mol –19 electronic charge e = –1.60 × 10 C 3 –1 molar volume of gas Vm = 22.4 dm mol at s.t.p. (101 kPa and 273 K) 3 –1 Vm = 24.0 dm mol at room conditions –14 2 –6 ionic product of water Kw = 1.00 × 10 mol dm (at 298 K (25 °C)) specific heat capacity of –1 –1 –1 –1 c = 4.18 kJ kg K (4.18 J g K ) water The Periodic Table of Elements Group 1 2 13 14 15 16 17 18 1 2 H He hydrogen helium Key 1.0 4.0 3 4 atomic number 5 6 7 8 9 10 Li Be atomic symbol B C N O F Ne lithium beryllium name boron carbon nitrogen oxygen fluorine neon 6.9 9.0 relative atomic mass 10.8 12.0 14.0 16.0 19.0 20.2 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar sodium magnesium aluminium silicon phosphorus sulfur chlorine argon 23.0 24.3 3 4 5 6 7 8 9 10 11 12 27.0 28.1 31.0 32.1 35.5 39.9 www.cambridgeinternational.org after the live examination series. 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton 39.1 40.1 45.0 47.9 50.9 52.0 54.9 55.8 58.9 58.7 63.5 65.4 69.7 72.6 74.9 79.0 79.9 83.8 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 20 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon 85.5 87.6 88.9 91.2 92.9 95.9 – 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57–71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 lanthanoids 11_9701_13_2023_1.10 Cs Ba Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn caesium barium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury thallium lead bismuth polonium astatine radon 132.9 137.3 178.5 180.9 183.8 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 – – – 87 88 89–103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 actinoids Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og francium radium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson – – – – – – – – – – – – – – – – – 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 lanthanoids La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium 138.9 140.1 140.9 144.4 – 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.1 175.0 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 actinoids Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium – 232.0 231.0 238.0 – – – – – – – – – – – International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment