Chemistry 9701/12 May/June 2022: question paper and mark scheme

Question

Equations involving four enthalpy changes are shown. Na(g) → Na+(g) + e– ΔH = W Na(g) → Na2+(g) + 2e– ΔH = X Na(s) → Na(g) ΔH = Y Na(s) → Na2+(g) + 2e– ΔH = Z Which equation represents the second ionisation energy of sodium? A X B X+Y–W C X–W D Z–W

Question

This question refers to isolated gaseous atoms in the ground state. In which atom are all electrons paired? A Ba B Br C S D Si

Question

Which sample contains the most iodine? A 1 g of CaI2 B 1 g of KI C 1 g of NaI D 1 g of NH4I

Question

When a small sample of hydrocarbon Q is completely combusted, it produces 3.52 g of carbon dioxide and 1.44 g of water. What could be the structure of hydrocarbon Q? A B C D H C C C C H

Question

Ethane and ethene are both hydrocarbon molecules. What is a feature of both molecules? A a planar structure B bond angles of 109° C σ covalent bonds D π covalent bonds

Question

Elements J and L are both in Group 15. J and L each form a gaseous covalent hydride in which their oxidation number is –3. In the liquefied forms of these hydrides, significant hydrogen bonding occurs only in the hydride of L. Which row about J and L could be correct? identity identity outer shell electron of J of L configuration A As N p5 B As N s2p3 C N As p5 D N As s2p3

Question

Which gas will behave least like an ideal gas at 150 °C and 101 kPa? A ammonia B fluorine C krypton D steam

Question

When an evacuated glass bulb of volume 200 cm3 is filled with a gas at 300 K and 101 kPa, the mass of the bulb increases by 0.68 g. The gas obeys the ideal gas equation. What is the identity of the gas? A argon B krypton C neon D nitrogen

Question

The standard enthalpy of formation of NO2(g) is + 33.2 kJ mol–1. The standard enthalpy of formation of N2O4(g) is + 9.2 kJ mol–1. What is the standard enthalpy change for the reaction 2NO2(g) → N2O4(g)? A –57.2 kJ mol–1 B –24.0 kJ mol–1 C +42.4 kJ mol–1 D +75.6 kJ mol–1

Question

Separate samples of 25.0 cm3 of 0.1 mol dm–3 NaOH(aq) are added to each of three different acid solutions, as described. The temperature of each of the solutions was 298 K before mixing. concentration volume sample acid type of acid / mol dm–3 / cm3 1 H2SO4 strong 0.05 25.0 2 HCl strong 0.05 25.0 3 CH3CO2H weak 0.05 25.0 Which statement describes the temperature rises that occur on mixing each of these three acids separately with NaOH? A The temperature rise in all three mixtures is the same. B The temperature rise using H2SO4 and HCl is the same. C The temperature rise using CH3CO2H is greater than using HCl. D The greatest temperature rise occurs using H2SO4.

Question

NCl 3 reacts with H2O. NCl 3 + 3H2O → NH3 + 3HCl O The oxidation state of nitrogen does not change in this reaction. Which statement is correct? A Chlorine is reduced. B Chlorine is oxidised. C Hydrogen is both oxidised and reduced. D This is not a redox reaction.

Question

In which row do the oxidation numbers of vanadium increase? smallest largest A VO43– VO3– VO2+ B VO2+ V2O3 VO43– C V2O3 VO2+ VO3– D VO43– VO2+ VO2+

Question

A synthesis for methanol is shown. CO2 + 3H2 CH3OH + H2O ΔH = – 49 kJ mol–1 Which conditions would produce the greatest yield of methanol at equilibrium? pressure temperature / °C A high 80 B high 20 C low 80 D low 20

Question

Hydrogen and iodine can react reversibly to produce hydrogen iodide. The equation is shown. H2(g) + I2(g) 2HI(g) 4.00 mol of hydrogen gas and X mol of iodine vapour are mixed in a sealed container of volume 1.00 dm3 at a temperature of 460 K. The system is allowed to reach equilibrium. The equilibrium mixture contains 2.00 mol of hydrogen iodide. The equilibrium constant, Kc, for the reaction at 460 K is 4.0. What is the value of X? A 0.50 mol B 1.17 mol C 1.33 mol D 2.50 mol

Question

A large amount of N2O(g) decomposes into nitrogen gas and oxygen gas in the presence of a tiny amount of a gold foil catalyst. The gold foil provides a solid surface on which the catalysed reaction takes place. The graph shows the concentration of N2O(g) against time as it decomposes. The graph is a straight line. concentration of N2O(g) 0 0 time / min 10 Which row describes: ● the change in rate of reaction as N2O(g) decomposes from 0 to 10 minutes ● the effect of adding more gold foil catalyst on the rate of decomposition of the same amount and concentration of N2O(g)? change in effect of adding more rate of reaction as gold foil on the N2O(g) decomposes rate of decomposition A none increases B none none C decreases increases D decreases none

Question

The Haber process for the manufacture of ammonia is represented by the equation shown. N2(g) + 3H2(g) 2NH3(g) ΔH = – 92 kJ mol–1 Which statement is correct about this reaction when the temperature is increased? A Both forward and backward rates increase. B The backward rate only increases. C The forward rate only increases. D There is no effect on the backward or forward rates.

Question

NH3(aq) is added to separate samples of NaCl (aq), MgCl 2(aq), BaCl 2(aq) and SiCl 4(l). Under the conditions of this experiment, only two samples will produce a white precipitate when NH3(aq) is added. What are these two samples? A MgCl 2(aq) and BaCl 2(aq) B MgCl 2(aq) and SiCl 4(l) C NaCl (aq) and BaCl 2(aq) D NaCl (aq) and SiCl 4(l)

Question

Why is the ionic radius of a sulfide ion larger than the ionic radius of a potassium ion? A Ionic radius always decreases with increasing atomic number. B Positive ions always have smaller radii than negative ions. C The potassium ion has more protons in its nucleus than the sulfide ion. D The sulfide ion is doubly charged; the potassium ion is singly charged.

Question

Which graph correctly shows relative electronegativity plotted against relative atomic radius for the elements Na, Mg, Al and Si? A B Si Al Al electronegativity Mg electronegativity Mg Na Si Na atomic radius atomic radius C D Na Si Mg Al electronegativity Al electronegativity Mg Si Na atomic radius atomic radius

Question

The table gives information about calcium carbonate and calcium hydroxide. Which row is correct? calcium hydroxide calcium carbonate is can be manufactured more soluble in water using calcium carbonate than calcium hydroxide as a starting material A no no B no yes C yes no D yes yes

Question

Q is a Group 2 metal. An excess of QCO3(s) is added to H2SO4(aq) followed by filtration. A sample of QSO4 is then obtained by evaporation of the filtrate. What could be the identity of Q? A barium, calcium or magnesium B barium or calcium only C calcium only D calcium or magnesium only

Question

X, Y and Z are three elements in Group 17. X2 has weaker covalent bonds than Y2. X2 has stronger instantaneous dipole–induced dipole forces between its molecules than Z2. Y2 is a stronger oxidising agent than Z2. What could be X, Y and Z? X Y Z A Br Cl I B Cl Br I C I Br Cl D I Cl Br

Question

Chlorine reacts with aqueous sodium hydroxide forming two chlorine-containing products. Which row shows the oxidation states of chlorine in the products under the conditions stated? oxidation state conditions of Cl in products A cold NaOH(aq) –1 and +3 B cold NaOH(aq) –1 and +5 C hot NaOH(aq) –1 and +3 D hot NaOH(aq) –1 and +5

Question

A catalytic converter reduces the amount of pollutants in the fumes from a car exhaust. Which row identifies a pollutant and shows how it is removed by the action of the catalyst? pollutant chemical removal A carbon dioxide reduced to carbon B carbon monoxide oxidised to carbon dioxide C oxides of nitrogen oxidised to nitric acid D unburnt hydrocarbons oxidised to carbon dioxide and hydrogen

Question

Solid R is added to a solution of ammonium nitrate and the mixture is heated. A gas is given off which turns red litmus to blue. What could be R? A aluminium chloride B magnesium chloride C sodium oxide D phosphorus oxide

Question

A skeletal formula is shown. What is the total number of stereoisomers including the one shown? A 4 B 6 C 8 D 16

Question

The molecular formula CH3 can represent an anion, a cation or a free radical. Species with the molecular formula CH3 can act as an electrophile, a free radical or a nucleophile depending on the number of outer shell electrons on the central carbon atom. How many outer shell electrons on the central carbon atom must be present for CH3 to act in these different ways? CH3 as an CH3 as a CH3 as a electrophile free radical nucleophile A 6 7 8 B 6 8 7 C 7 6 8 D 8 7 6

Question

Compound Z, C7H13Br, has two chiral centres. A sample of Z contains all four possible optical isomers. This sample of Z reacts with hot ethanolic NaOH to produce a mixture of only three isomers. Two of these isomers are optical isomers of each other. What could be the formula of Z? A B C D Br Br Br Br

Question

The free-radical substitution reaction between methane and chlorine involves initiation, propagation and termination stages. Which row is correct? involved in radical produced in initiation stage a propagation stage A homolytic fission H• B homolytic fission CH3• C heterolytic fission H• D heterolytic fission CH3•

Question

The alkene shown reacts with an excess of HBr via an electrophilic addition reaction. What is the major product formed? A 3,5-dibromo-2-methylhexane B 2,5-dibromo-2-methylhexane C 2,6-dibromo-2-methylhexane D 3,6-dibromo-2-methylhexane

Question

The diagram shows the structures of two halogenoalkanes, P and Q. P Q C 2H 5 C 2H 5 CH3 C C 3H 7 CH3 C C 3H 7 Br F Both compounds can be hydrolysed. Which row is correct? compound more reaction mechanism readily hydrolysed A P SN1 B P SN2 C Q SN1 D Q SN2

Question

The structure of coniine is shown. coniine N CH2CH2CH3 H Coniine can be synthesised by reacting ammonia with a dibromo compound, X. X NH3 + C8H16Br2 → coniine + 2HBr What is compound X? A 1,1-dibromo-2-propylcyclopentane B 1,2-dibromo-2-propylcyclopentane C Br(CH2)3CHBr(CH2)3CH3 D Br(CH2)4CHBr(CH2)2CH3

Question

Primary alcohols can be oxidised to aldehydes using either acidified potassium dichromate(VI) or acidified potassium manganate(VII). The reaction mixtures change colour as the oxidising agent is reduced. What are the colour changes seen? acidified potassium dichromate(VI) acidified potassium manganate(VII) before after before after A green orange purple colourless B orange green colourless purple C orange green purple colourless D purple colourless orange green

Question

Which reaction has a product that gives a yellow precipitate when treated with alkaline I2(aq)? A 2-chloropropane is warmed with a dilute aqueous solution of sodium hydroxide. B Ethanal is heated under reflux with acidified potassium dichromate(VI). C Methyl ethanoate is heated under reflux with dilute sulfuric acid. D Propanal is reacted with NaBH4, followed by dilute sulfuric acid.

Question

The skeletal formula of M is shown. M O OH HO O M is reacted with an excess of LiAl H4. Dilute acid is then added. What is the molecular formula of the final organic product? A C5H6O5 B C5H10O4 C C5H10O3 D C5H12O3

Question

Which compound forms a precipitate when mixed with 2,4-DNPH reagent and also forms a precipitate when mixed with Fehling’s reagent? A B C D O O O O O O OH O

Question

Which reaction is a redox reaction? A ethanenitrile heated under reflux with dilute hydrochloric acid B ethanoic acid reacted with aqueous sodium hydroxide C ethanoic acid reacted with sodium D ethyl ethanoate heated under reflux with dilute hydrochloric acid

Question

Ethyl butanoate is a flavouring, with a fruity flavour. Which row is correct? alcohol and acid that react the mass of water formed to form ethyl butanoate when 2.32 g of ester is formed O A and OH 0.36 g OH O B and OH 0.40 g OH O C and OH 0.36 g OH O D and OH 0.40 g OH

Question

Cyclohexene, as shown in the diagram, can form an addition polymer. cyclohexene Which structure represents a section of the polymer? A B C D

Question

Three organic compounds are listed. 1 ethanal 2 propan-1-ol 3 propan-2-ol Which compounds will have a mass spectrum that contains a fragment peak at m / e = 43? A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3 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 = 6.02 × 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 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 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 – – – – – – – – – – –