Chemistry 9701/12 October/November 2024: question paper and mark scheme

Question

Which species contains a different number of electrons from the other three? A Cl O4– B H2SO4 C SO42– D Te2–

Question

Which factor causes helium to have a higher first ionisation energy than hydrogen? A In the 1s orbital in helium, electrons are paired. B The lowest energy level in helium is filled. C The nuclear charge in helium is higher than in hydrogen. D There is less shielding of the outer shell in helium.

Question

A 0.216 g sample of aluminium carbide reacts with an excess of water to produce methane gas. This is the only carbon-containing product formed in the reaction. This methane gas burns completely in O2 to form H2O and CO2 only. The volume of CO2 produced at room temperature and pressure is 108 cm3. What is the formula of aluminium carbide? A Al 2C3 B Al 3C2 C Al 3C4 D Al 4C3

Question

A reaction between two gases takes place on the surface of the catalytic converter of a petrol-engined car. In this reaction, four reactant molecules produce three product molecules. What could be the two reactant gases in this reaction? A nitrogen and carbon dioxide B nitrogen monoxide and carbon dioxide C nitrogen monoxide and carbon monoxide D nitrogen dioxide and carbon monoxide

Question

An ion contains 1 nitrogen atom and 2 hydrogen atoms. It has an H–N–H bond angle of approximately 105°. Which row is correct? number of lone overall charge pairs around on ion N in ion A 1 +1 B 2 +1 C 1 –1 D 2 –1

Question

Why does ICl have a higher boiling point than Br2? A because of the difference in the bond energies of the covalent bonds within ICl and Br2 B because of the difference in the polar nature of ICl and Br2 C because of the difference in the number of electrons contained within ICl and Br2 D because of the difference in the relative molecular mass of ICl and Br2

Question

In this question you may assume that nitrogen behaves as an ideal gas. One atmosphere pressure = 101 kPa. Which volume does 1.0 g of nitrogen occupy at 50 °C and a pressure of 2.0 atmospheres? A 70 cm3 B 150 cm3 C 470 cm3 D 950 cm3

Question

Which statement about the properties associated with the different types of bonding involved is correct? A Any covalent compound that contains both oxygen and hydrogen in its molecule forms hydrogen bonds. B Ionic bonds and covalent bonds cannot both occur in the same compound. C Ionic compounds differ from metals in that ionic compounds do not conduct electricity in the solid state. D The only covalent compounds with high melting points are those in which hydrogen bonds occur.

Question

For which reaction is the enthalpy change an enthalpy change of formation? A C(g) + 2H2(g) → CH4(g) B 1 2 N2(g) + 1 2 O2(g) → NO(g) C Na2O(s) + SO3(g) → Na2SO4(s) D PCl 3(g) + Cl 2(g) → PCl 5(g)

Question

Two standard enthalpy change of formation values are given. [VCl 2] = –452 kJ mol–1 [VCl 3] = –573 kJ mol–1 What is the enthalpy change for the reaction 3VCl 2 → 2VCl 3 + V ? A –210 kJ mol–1 B –121 kJ mol–1 C +121 kJ mol–1 D +210 kJ mol–1

Question

Equations for some reactions of hydrogen peroxide are given. 1 2Fe2+ + H2O2 + 2H+ → 2Fe3+ + 2H2O 2 2MnO4– + 5H2O2 + 6H+ → 2Mn2+ + 8H2O + 5O2 3 2Fe3+ + H2O2 + 2OH– → 2Fe2+ + O2 + 2H2O In which reactions is hydrogen peroxide acting as a reducing agent? A 1 and 3 B 1 only C 2 and 3 D 2 only

Question

The equation for the reaction of aqueous thiosulfate ions, S2O32–, and aqueous dioxo-vanadium ions, VO2+, is shown. 2S2O32– + xVO2+ + yH+ → S4O62– + zVO2+ + 2H2O Which row shows two correct statements about the equation for this reaction? change in oxidation comparison of x and y to z number of vanadium A x and z are the same value from +4 to +5 and quarter the value of y B x and z are the same value from +5 to +4 and quarter the value of y C x and z are the same value from +5 to +4 and half the value of y D x and z are the same value from +4 to +5 and half the value of y

Question

When some solid Ca5(PO4)3OH is added to a beaker of water, an equilibrium is set up. Ca5(PO4)3OH(s) 5Ca2+(aq) + 3PO43–(aq) + OH–(aq) Which compound, when added to the equilibrium mixture, increases the amount of Ca5(PO4)3OH(s) present? A NH3 B NH4Cl C CH3CO2H D NaCl

Question

Gaseous hydrogen and gaseous iodine react to form gaseous hydrogen iodide. H2(g) + I2(g) 2HI(g) In an experiment, 2.0 mol of hydrogen and 2.0 mol of iodine are placed in a sealed container of volume 1.0 dm3. The Kc value for this reaction under the conditions used is 9.0. How many moles of hydrogen iodide are present at equilibrium? A 0.57 mol B 1.2 mol C 1.5 mol D 2.4 mol

Question

Why does the rate of a gaseous reaction increase when the pressure is increased at a constant temperature? A More particles have energy that exceeds the activation energy. B The particles have more space in which to move. C The particles move faster. D There are more frequent collisions between particles.

Question

The Boltzmann distribution for a mixture of gases capable of reaction is shown. The two curves represent the mixture of gases at 25 °C and at 35 °C. The activation energies for the catalysed and uncatalysed reactions are shown. Ea catalysed number of particles w Ea uncatalysed x y 0 0 z energy Which row is correct? number of particles with number of particles with enough energy to react at 25 °C enough energy to react at 35 °C in the catalysed reaction in the uncatalysed reaction A w+x+y+z z B w+x+y+z x+z C y+z z D y+z x+z

Question

Which oxide is insoluble in aqueous sodium hydroxide? A MgO B Al 2O3 C P4O10 D SO2

Question

Sodium and sulfur are burned separately in oxygen. Each reaction has a distinctive coloured flame. Which row is correct? Na + O2 S + O2 A white flame blue flame B white flame yellow flame C yellow flame blue flame D yellow flame yellow flame

Question

X and Y are elements in Period 3 of the Periodic Table. Y has a greater atomic number than X. The stable ion formed by Y has a greater radius than the stable ion formed by X. The stable ion formed by Y has 18 electrons. Which row is correct? number of element with electrons in the the greater stable ion of X atomic radius A 10 X B 10 Y C 18 X D 18 Y

Question

X is a Group 2 element in either Period 3 or Period 5. X(OH)2 is less soluble in water than Ca(OH)2. When X(NO3)2 is heated, it decomposes. Which row is correct? equation describing identity of X decomposition of X(NO3)2 A Mg X(NO3)2 → X + 2NO2 + O2 B Mg 2X(NO3)2 → 2XO + 4NO2 + O2 C Sr X(NO3)2 → X + 2NO2 + O2 D Sr 2X(NO3)2 → 2XO + 4NO2 + O2

Question

Which statement comparing magnesium and barium, or their compounds, is correct? A Magnesium reacts with dilute hydrochloric acid more rapidly than barium does. B One mole of magnesium carbonate gives off a greater amount of gas when it reacts with an excess of dilute hydrochloric acid than one mole of barium carbonate does. C The solubility of magnesium sulfate in water is greater than the solubility of barium sulfate in water. D Magnesium carbonate undergoes thermal decomposition less readily than barium carbonate does.

Question

The colours of the silver halides AgCl, AgBr and AgI differ. The solubilities of these halides in aqueous ammonia also differ. Which row is correct? silver halide that is colour of AgBr most soluble in NH3(aq) A cream AgCl B cream AgI C yellow AgCl D yellow AgI

Question

The name ‘chlorate’ is used for an anion consisting of chlorine and oxygen only. In a molecule of ICl, the iodine atom has oxidation number x and the chlorine atom has oxidation number y. When ICl is added to H2O, iodine is reduced. 4ICl + 2H2O → 4HCl + O2 + 2I2 Which statement about the value of x or y is correct? A x is the same as the oxidation number of Cl in the chlorate ion formed when Cl 2(aq) is added to cold NaOH(aq). B x is the same as the oxidation number of Cl in the chlorate ion formed when Cl 2(aq) is added to hot NaOH(aq). C y is the same as the oxidation number of Cl in the chlorate ion formed when Cl 2(aq) is added to cold NaOH(aq). D y is the same as the oxidation number of Cl in the chlorate ion formed when Cl 2(aq) is added to hot NaOH(aq).

Question

Which statement is correct? A An ammonium ion is basic due to a lone pair of electrons on the nitrogen atom. B Nitrogen monoxide, NO, reacts with peroxyacetyl nitrate to produce a component of photochemical smog. C Nitrogen dioxide catalyses the oxidation of atmospheric sulfur dioxide. D Nitrogen is very unreactive due to the very strong permanent dipole–permanent dipole attractions between the nitrogen atoms.

Question

The diagram shows the structural formula of a hydrocarbon molecule Q. molecule Q H H H C H C H H C H H H C C C C C C C H H H How many of the carbon atoms in molecule Q are sp2 hybridised? A 3 B 4 C 7 D 10

Question

Compound X is found in cell walls of some bacteria. Its structural formula is shown. compound X CH3(CH2)17CH=CH(CH2)17CH(OH)CH(CH3)CO2H How many stereoisomers are there with this structural formula? A 2 B 4 C 6 D 8

Question

Structural isomerism only should be considered when answering this question. How many straight-chain isomers are there with molecular formula C4H8Cl 2? A 6 B 7 C 8 D 9

Question

What is true of every nucleophile? A It attacks a double bond. B It donates a lone pair of electrons. C It is a single atom. D It is negatively charged.

Question

The diagram shows a synthetic route to produce 1-methylcyclohexanol. CH3 CH3 OH HBr product heat X reagent Y What is reagent Y? A aqueous NaOH B cold dilute KMnO4 C ethanolic NaOH D hot concentrated KMnO4

Question

X and Y are the reagents required to convert 1-bromopropane into butanoic acid. H H H H H H H H H O X Y H C C C Br H C C C CN H C C C C H H H H H H H H H OH What are the correct identities of reagents X and Y? X Y A NH3 HCl (aq) B KCN in C2H5OH NaOH(aq) C KCN in C2H5OH HCl (aq) D HCN NaOH(aq)

Question

The table shows three sets of reagents and reaction conditions. reagents reaction conditions 1 CH2C(CH3)CH3 and HCl (g) room temperature 2 CH3C(CH3)(OH)CH3 and SOCl 2 room temperature 3 CH3CH(CH3)CH3 and Cl 2 the presence of ultraviolet light Which sets of reagents and conditions can be used to produce 2-chloro-2-methylpropane as one of the organic products? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

What are the only structures formed when butan-2-ol is heated with concentrated H2SO4? CH3CH2 H CH3 H A C C C C H H H CH3 CH3 CH3 CH3 H H H B C C C C C C H H H CH3 CH3CH2 H H H H H C C C C C CH3CH2 H CH3 CH3 CH3 H CH3CH2 H H H D C C C C C C CH3 H H H CH3 CH3

Question

The compound ‘leaf alcohol’ is partly responsible for the smell of new-mown grass. leaf alcohol CH3CH2CH=CHCH2CH2OH What will be formed when ‘leaf alcohol’ is oxidised using an excess of hot acidified K2Cr2O7(aq)? A CH3CH2CH(OH)CH(OH)CH2CO2H B CH3CH2COCOCH2CO2H C CH3CH2CH=CHCH2CO2H D CH3CH2CO2H and HO2CCH2CO2H

Question

Compound X: ● does not react with Tollens’ reagent ● forms a yellow precipitate with alkaline I2(aq) ● does not react with sodium. What could be the identity of X? A CH3CHO B C2H5COCH3 C CH3COOC2H5 D CH3CHOHCH3

Question

Which compound can undergo nucleophilic addition? A bromoethane, C2H5Br B ethanal, CH3CHO C ethane, C2H6 D ethene, C2H4

Question

C2H5COOCH3 is reacted with aqueous acid. The products from this reaction are reacted with LiAl H4 to form two molecules Y and Z. What are the identities of molecules Y and Z? A both molecules are C2H5OH B CH3OH and CH3CHOHCH3 C CH3OH and C2H5OH D CH3OH and C2H5CH2OH

Question

A sample of propanoic acid of mass 3.70 g reacts with an excess of magnesium. A second sample of propanoic acid of mass 3.70 g reacts with an excess of sodium. Both reactions go to completion forming a gas. Which row is correct? volume of gas formed volume of gas formed with magnesium with sodium at s.t.p. / cm3 at s.t.p. / cm3 A 560 560 B 560 1120 C 1120 560 D 1120 1120

Question

Which statement about H2C=C(CH3)CH2CO2CH3 is correct? A It can be hydrolysed to a secondary alcohol. B It can be made using ethanoic acid and a suitable alcohol. C It gives a positive test with alkaline I2(aq). D When treated with hot concentrated acidified KMnO4 it gives CH3COCH2COOH as one product.

Question

Synthetic resins can be made by polymerisation of a variety of monomers including prop-2-en-1-ol, CH2=CHCH2OH. Which structure represents the repeat unit in the polymer poly(prop-2-en-1-ol)? A CH2 CH2 CH2 O B CH2 CH CH2OH C CH C CH2OH D CH2 CH2 CH OH

Question

Vitamin C has the structure shown. HO HO O O HO OH The mass spectrum of vitamin C has a molecular ion peak with an m/e value of 176 and a relative abundance of 7.0%. What is the abundance of the M +1 peak? A 0.462% B 0.539% C 0.616% D 0.693% Important values, constants and standards molar gas constant R = 8.31 J K–1 mol–1 Faraday constant F = 9.65 × 104 C mol–1 Avogadro constant L = 6.022 × 1023 mol–1 electronic charge e = –1.60 × 10–19 C molar volume of gas Vm = 22.4 dm3 mol–1 at s.t.p. (101 kPa and 273 K) Vm = 24.0 dm3 mol–1 at room conditions ionic product of water Kw = 1.00 × 10–14 mol2 dm–6 (at 298 K (25 °C)) specific heat capacity of water c = 4.18 kJ kg–1 K–1 (4.18 J g–1 K–1) 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 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 16 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 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 138.9 140.1 140.9 144.2 – 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 – – – – – – – – – – –