Chemistry 9701/12 February/March 2023: question paper and mark scheme

Question

Four equations representing reactions of nitrogen or one of its compounds are given. Which equation represents a disproportionation reaction? A 2HNO3 + CaCO3 → Ca(NO3)2 + CO2 + H2O B N2 + 3H2 → 2NH3 C NH4Cl + NaOH → NH3 + NaCl + H2O D 2NO2 + H2O → HNO3 + HNO2

Question

The diagram shows the Boltzmann distribution for one mole of a gas. The gas takes part in a reaction with an activation energy, Ea. P number of particles with energy, E 0 0 Ea energy, E Which statement correctly describes the effect of an increase in temperature? A Peak P will be higher and fewer molecules will have energy > Ea. B Peak P will be higher and more molecules will have energy > Ea. C Peak P will be lower and fewer molecules will have energy > Ea. D Peak P will be lower and more molecules will have energy > Ea.

Question

A student carries out four experiments to investigate the rate of reaction between 3.0 g of calcium carbonate and hydrochloric acid. CaCO3(s) + 2HCl (aq) → CaCl 2(aq) + CO2(g) + H2O(l) –3 experiment 1 CaCO3 powder + 2.0 mol dm HCl at 35 °C –3 experiment 2 CaCO3 powder + 2.0 mol dm HCl at 35 °C –3 experiment 3 large chips of CaCO3 + 1.0 mol dm HCl at room temperature –3 experiment 4 large chips of CaCO3 + 1.0 mol dm HCl at 35 °C The student collects the CO2(g) and times how long it takes to produce the same volume of gas for each experiment. What could be the correct times for the four experiments? experiment 1 experiment 2 experiment 3 experiment 4 /s /s /s /s A 5 10 30 95 B 5 10 95 30 C 5 30 95 10 D 95 30 10 5

Question

The table shows the partial pressures in an equilibrium mixture formed by the Haber process. 3H2(g) + N2(g) ⇌ 2NH3(g) substance partial pressure / kPa nitrogen 7000 hydrogen 8000 ammonia 4000 What is the numerical value of the equilibrium constant, Kp, for this reaction? –9 –5 –5 8 A 4.46 × 10 B 4.76 × 10 C 7.14 × 10 D 2.24 × 10

Question

A reversible reaction is shown. ∆H = +77.0 kJ mol –1 2NOCl (g) ⇌ 2NO(g) + Cl 2(g) Which change in conditions will move the position of equilibrium to the right and increase the value of the equilibrium constant? A a decrease in pressure B a decrease in temperature C an increase in pressure D an increase in temperature x+ y+

Question

The ore psilomelane may be considered to have the general formula Ba(Mn )(Mn )8O16(OH)4. In this general formula, x+ and y+ are the two different oxidation states of manganese in psilomelane. What could be the values of x and y? x y A 2 4 B 6 4 C 6 3 D 7 3

Question

Silicon reacts with a mixture of calcium oxide and magnesium oxide at 1200 °C. 2MgO + 2CaO + Si → 2Mg + Ca2SiO4 Which statement about this reaction is correct? A Calcium is reduced and silicon is neither oxidised nor reduced. B Magnesium is reduced and calcium is neither oxidised nor reduced. C Magnesium is reduced and silicon is neither oxidised nor reduced. D Silicon is reduced and calcium is neither oxidised nor reduced.

Question

In which species is there a lone pair of electrons? + – A CH3 B CH3 C CH3 D CH4

Question

Under which conditions will nitrogen behave most like an ideal gas? temperature pressure A low high B high low C low low D high high

Question

The equation for a chemical reaction is shown. All substances are in their standard states. XeF6 + 3H2O → XeO3 + 6HF Which statement describes the standard enthalpy change of reaction for this reaction? A the enthalpy change when a total of one mole of products is produced B the enthalpy change when a total of one mole of reactants is reacted C the enthalpy change when one mole of water reacts D the enthalpy change when six moles of hydrogen fluoride are produced

Question

Molten aluminium chloride has a simple molecular structure. Each molecule consists of two aluminium atoms and six chlorine atoms. Which statement is correct? A All the chlorine atoms in 1 g of molten aluminium chloride have the same mass. 23 B One mole of molten aluminium chloride contains 6.02 × 10 aluminium atoms. 24 C One mole of molten aluminium chloride contains 3.61 × 10 chlorine atoms. D The empirical formula of molten aluminium chloride is Al 2Cl 6.

Question

Which atom contains four times as many neutrons as the atom? A B C D

Question

Which statement about the first ionisation energies of magnesium and neon is correct? A Magnesium has the greater numerical value and both are endothermic. B Magnesium has the greater numerical value and both are exothermic. C Neon has the greater numerical value and both are endothermic. D Neon has the greater numerical value and both are exothermic.

Question

In a sample of pure water, what is the maximum number of hydrogen bonds that one molecule of water can be involved in? A 1 B 2 C 3 D 4

Question

Hydrated cobalt(II) sulfate loses water when heated to give anhydrous cobalt(II) sulfate. All the water of crystallisation is lost to the atmosphere as steam. When 3.10 g of hydrated cobalt(II) sulfate, CoSO4•xH2O, is heated to constant mass the loss in mass is 1.39 g. What is the value of x, to the nearest whole number? A 4 B 6 C 7 D 11

Question

The table shows bond energies for some diatomic molecules. Deuterium, D, is an isotope of hydrogen. energy bond –1 / kJ mol F–F 158 Cl –Cl 242 Br–Br 193 I–I 151 H–H 436 D–D 442 Which statements are correct? 1 Diatomic molecules have exact values for their bond energies, which are always positive. 2 The trend in Group 7 bond energies can be explained by the variation in instantaneous dipole–induced dipole (id–id) forces. 3 A value for the enthalpy change for the reaction between deuterium and chlorine can be calculated using these data alone. A 1 only B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Two procedures are described. 1 Sulfur is burned in an excess of oxygen and then NO is added to the product mixture. 2 Sulfur is burned in an excess of oxygen and then NO2 is added to the product mixture. Which procedures will produce some sulfur trioxide, SO3? A both 1 and 2 B 1 only C 2 only D neither 1 nor 2

Question

Powder P is a mixture containing two of AgCl , AgBr or AgI. P is shaken with dilute aqueous ammonia. A yellow solid, Q, remains. The mixture is filtered and Q is washed and dried. The filtrate is collected and treated with aqueous nitric acid to produce a white precipitate, R, which is filtered off, washed and dried. Q and R are warmed separately with concentrated sulfuric acid, H2SO4. Which observations are made? Q + concentrated H2SO4 R + concentrated H2SO4 A violet fumes orange fumes B violet fumes steamy fumes C steamy fumes violet fumes D orange fumes steamy fumes

Question

Two Period 3 elements, X and Y, burn separately in oxygen to form solid oxides. The oxide of X is insoluble in water. The oxide of Y dissolves in water to form a solution which dissolves the oxide of X. What could X and Y be? X Y A aluminium sodium B magnesium sodium C silicon phosphorus D silicon sulfur

Question

Which row describes the structure and bonding of SiO2 and SiCl 4? SiO2 SiCl 4 structure bonding structure bonding A giant covalent giant covalent B giant covalent simple covalent C giant ionic giant covalent D giant ionic simple covalent

Question

A sample containing 0.010 mol of anhydrous calcium nitrate is heated strongly until it fully decomposes. All the gas produced is collected and its volume measured at room conditions. What is the volume of gas produced? 3 3 3 3 A 120 cm B 600 cm C 720 cm D 840 cm

Question

V and Z are both elements in Period 3 of the Periodic Table. Each element forms one stable ion that does not contain another element. The atomic radius of each element and the ionic radius of the ion described above is shown. atomic radius ionic radius element / nm / nm V 0.186 0.095 Z 0.099 0.181 Which statement is correct? A Ions of V and Z have the same number of full electron shells. B Ions of Z are positively charged. C Z has a greater electronegativity than V. D V has more outer electrons than Z.

Question

In Group 2 of the Periodic Table, the properties of the elements and their compounds show regular change down the group. Which property shows a decrease from magnesium to barium? A the decomposition temperature of the carbonates B the decomposition temperature of the nitrates C the solubility of the hydroxides D the solubility of the sulfates

Question

Four properties of beryllium, Be, or a beryllium compound are listed. Which property is different from the property of magnesium or the equivalent magnesium compound? A Be reacts with O2 when heated in air; Mg does not. B Be reacts with aqueous H2SO4 to form a metal sulfate and H2; Mg does not. C Be(NO3)2 decomposes on heating to form a metal oxide, NO2 and O2; Mg(NO3)2 does not. D BeCl 2 reacts with water to form fumes of HCl ; MgCl 2 does not.

Question

Which two formulae correctly represent a pair of structural isomers? A CH3CH(CH3)COOH and (CH3)2CHCOOH B CH3CH(COOH)CH3 and (CH3)2CHCOOH C CH3CHCOOH and CH3CH2CH2COOH D CH3CH2CH2COOH and (CH3)2CHCOOH

Question

Which reagents and conditions would result in the formation of butanenitrile, CH3CH2CH2CN? A 1-bromobutane heated under pressure with ammonia in ethanol B 1-bromopropane heated with potassium cyanide in ethanol C propanal heated with hydrogen cyanide in the presence of potassium cyanide D propanone heated with hydrogen cyanide in the presence of potassium cyanide

Question

Compound X, C7H13Br, reacts with hot alcoholic NaOH to produce two compounds, Y and Z. On reaction with Br2, Y gives a product, C7H12Br2, which exists as a mixture of four optical isomers. On reaction with Br2, Z gives a product, C7H12Br2, which is non-chiral. What could X be? A B C D CH3 Br CH2Br CH3 CH3 Br Br

Question

When illudin S is heated under reflux with an excess of acidified potassium dichromate(VI), compound M is formed. illudin S OH compound M OH HO O What is the molecular formula of compound M? A C15H16O4 B C15H16O5 C C15H18O4 D C15H18O5

Question

Cyclohexene, C6H10, is a hydrocarbon with a six-membered ring of carbon atoms. It has several structural isomers that are straight-chain alkenes. The number of double bonds in each of these molecules is P. What is the shape of the cyclohexene molecule and what is the value of P? shape P A planar 1 B planar 2 C non-planar 1 D non-planar 2

Question

Exhaust gases from an internal combustion engine are made less harmful by passing them through a catalytic converter. A number of reactions take place in the catalytic converter. Two such reactions are described in the table. Which row is correct? the type of reaction that the type of reaction that removes unburned removes carbon monoxide hydrocarbons A oxidation oxidation B oxidation reduction C reduction reduction D reduction oxidation

Question

Which compound reacts most rapidly with aqueous silver nitrate by an SN1 mechanism? A 1-chloromethylpropane B 2-chloromethylpropane C 1-iodomethylpropane D 2-iodomethylpropane

Question

Tartaric acid, HOOCCH(OH)CH(OH)COOH, is found in many plants. A sample of tartaric acid reacts with an excess of LiAl H4 to form the organic product J. What happens when NaOH(aq) is added to separate samples of tartaric acid and J? A Both tartaric acid and J react. B Only tartaric acid reacts. C Only J reacts. D Neither tartaric acid nor J react.

Question

Citric acid can be converted into tricarballylic acid in two stages. An intermediate, Q, is formed. CH2 COOH CH2 COOH stage 1 stage 2 HO C COOH Q CH COOH CH2 COOH CH2 COOH citric acid tricarballylic acid Which reagents are needed for each stage? stage 1 stage 2 A concentrated H2SO4 H2(g) and Ni B concentrated H2SO4 LiAl H4 C LiAl H4 H2SO4(aq) D NaOH(aq) H2(g) and Ni

Question

Structural and stereoisomerism should be considered when answering this question. P has molecular formula C5H10O. P produces an orange precipitate with 2,4-dinitrophenylhydrazine (2,4-DNPH reagent). How many isomeric structures does P have? A 5 B 6 C 7 D 8

Question

Two isomeric alcohols, W and X, have molecular formula C4H9OH. W is oxidised to carbonyl compound Y which gives a red precipitate with Fehling’s solution. X is oxidised to carbonyl compound Z which does not give a red precipitate with Fehling’s solution. Which of W and X gives a yellow precipitate with alkaline I2(aq)? A insufficient data is given to answer this question B W only C X only D neither W nor X

Question

The ester ethyl butanoate can be hydrolysed using an excess of dilute sodium hydroxide solution. Which substance is a product of this reaction? A CH3CH2CH2CO2Na B CH3CO2Na C CH3CH2ONa D H2O

Question

An aqueous solution contains 4.00 g of a carboxylic acid, Q. When this solution reacts with an 3 excess of magnesium, 380 cm of gas is produced, measured at s.t.p. What is the relative formula mass of Q? A 59 B 118 C 126 D 236

Question

The infrared spectrum of an organic compound 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 2850–3100 N–H amine, amide 3300–3500 O–H carboxyl 2500–3000 hydroxy 3200–3650 Which compound could give this spectrum? A CH3CH2CO2H B CH3CH(OH)CH3 C CH3COCH3 D CH3COCH2OH

Question

Cyclohexa-1,4-diene is treated with a solution of bromine in tetrachloromethane in the dark. cyclohexa-1,4-diene Which product is formed? A B C D Br Br Br Br Br Br Br Br Br Br Br Br Br Br 40 2-methylbut-2-ene is reacted with hot, concentrated, acidified potassium manganate(VII) solution. What are the products of this reaction? A ethanal and propanone B ethanoic acid and propanone C ethanoic acid and propan-2-ol D ethanol and propan-2-ol 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) 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. 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 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 03_9701_12_1.18 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 138.9 140.1 140.9 144.4 – 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 – – – – – – – – – – –

Question

In the question paper above.