Chemistry 9701/12 February/March 2022: question paper and mark scheme

Question

The first ionisation energy of potassium, K, is 418 kJ mol–1. The first ionisation energy of strontium, Sr, is 548 kJ mol–1. Which statement helps to explain why Sr has a greater first ionisation energy than K? A The charge on a Sr nucleus is greater than the charge on a K nucleus. B The outer electron in a Sr atom experiences greater shielding than the outer electron in a K atom. C The outer electron in a Sr atom experiences spin-pair repulsion. D The outer electron in a Sr atom is further from the nucleus than the outer electron in a K atom.

Question

What is the electronic configuration of Mg2+? A 1s2 2s2 2p6 B 1s2 2s2 2p6 3s2 C 1s2 2s2 2p6 3s2 3p2 D 1s2 2s2 2p6 3s2 3p6 3d2 4s2

Question

Compound X contains the elements C, H and O only. 2.00 g of X produces 4.00 g of carbon dioxide and 1.63 g of water when completely combusted. What is the empirical formula of X? A CHO2 B C2H2O C C2H4O D CH2O2

Question

For which molecule is the dipole moment zero? A CH3Cl B CH2Cl 2 C CHCl 3 D CCl 4

Question

Which dot-and-cross diagram is correct for Al 2Cl 6? A B 3+ – Cl key 2 Al 6 Cl = eectrons from Al = eectrons from Cl Cl Al Cl Cl Al Cl Cl C D Cl Cl Cl Cl Al Cl Cl Al Al Cl Cl Al Cl Cl Cl Cl

Question

The boiling points of some hydrogen halides are shown. hydrogen halide boiling point / K H–Cl 188 H–Br 206 H–I 238 What is the explanation for the trend in boiling point for the hydrogen halides from HCl to HI? A The bond energies of the hydrogen halides increase from HCl to HI. B There is an increase in the strength of the intermolecular forces of attraction from HCl to HI. C The intermolecular hydrogen bonds become stronger from HCl to HI. D There is an increase in the bond polarity from HCl to HI.

Question

Elements X, Y and Z are all in the first two periods of the Periodic Table. Their Pauling electronegativity values, EN, are shown. element EN X 1.0 Y 2.1 Z 4.0 Substances exist with formulae XZ, YZ and Z2. Which row puts these substances in order of increasing melting point? lowest highest melting point melting point A XZ YZ Z2 B XZ Z2 YZ C Z2 YZ XZ D Z2 XZ YZ

Question

The equation for reaction 1 is shown. reaction 1 C6H12O6 → 2CO2 + 2C2H5OH C6H12O6 a C2H5OH b What is the correct expression for the enthalpy change of reaction 1? A a+b B a–b C a + 2b D a – 2b

Question

Nitrogen monoxide is an atmospheric pollutant that is formed inside car engines by an endothermic reaction between nitrogen and oxygen. N2(g) + O2(g) → 2NO(g) Which diagram correctly represents the energy profile for this reaction? A B products products energy Ea energy Ea reactants H reactants H 0 0 0 progress of 0 progress of reaction reaction C D reactants Ea reactants Ea energy H energy H products products 0 0 0 progress of 0 progress of reaction reaction

Question

Two half-equations are shown. MnO4– + 2H2O + 3e– → MnO2 + 4OH– 2OH– + SO32– → SO42– + H2O + 2e– The equation for the reaction between manganate(VII) ions and sulfite ions is shown. uMnO4– + vH2O + wSO32– → xMnO2 + ySO42– + zOH– Which statements are correct? 1 u=x=z 2 Manganese is reduced to oxidation state +4. 3 Sulfur is oxidised from oxidation state +4 to +6. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Hydrogen peroxide, H2O2, decomposes to form water and oxygen. The reaction is catalysed by bromide ions. step 1 2Br –(aq) + H2O2(aq) + 2H+(aq) → 2H2O(l) + Br2(aq) step 2 H2O2(aq) + Br2(aq) → 2Br –(aq) + 2H+(aq) + O2(g) Which row is correct? type of catalyst in step 1 A heterogeneous bromide ions are oxidised B heterogeneous bromide ions are reduced C homogeneous bromide ions are oxidised D homogeneous bromide ions are reduced

Question

Hydrogen and iodine react to form hydrogen iodide in an exothermic reaction. The equation is shown. H2(g) + I2(g) 2HI(g) A 1 m3 reaction vessel contains H2, I2 and HI gases at equilibrium. The temperature is changed such that the total pressure in the 1 m3 vessel doubles. What is the effect on the value of Kp and on the position of equilibrium? effect on the effect on the value of Kp position of equilibrium A decreases moves left B increases moves right C no change moves left D no change no change

Question

Diethylzinc, (C2H5)2Zn, is added to NaOH(aq). Two reactions occur. reaction 1 (C2H5)2Zn + H2O → ZnO + 2C2H6 reaction 2 H2O + ZnO + 2OH– → Zn(OH)42– In these reactions, which compounds act as Brønsted–Lowry acids? reaction 1 reaction 2 A (C2H5)2Zn H2O B H2O H2O C H2O ZnO D the reaction is not acid / base ZnO

Question

Which statement about atoms and molecules is correct? A The molecular formula of a compound is the simplest whole number ratio of atoms of each element in the compound. B One mole of any substance contains 6 × 1023 atoms. C The relative atomic mass of an element is the ratio of the average mass of one atom of the element to the mass of an atom of carbon-12. D The relative formula mass of a compound is the sum of the individual atomic masses of all the atoms in the formula.

Question

The Boltzmann distribution for one mole of a gas at temperature T is shown. number of particles with energy, E 0 0 energy, E One mole of the same gas is added, and the gas remains at temperature T. Which dotted curve shows the distribution with the added gas? A B number of number of particles with particles with energy, E energy, E 0 0 0 energy, E 0 energy, E C D number of number of particles with particles with energy, E energy, E 0 0 0 energy, E 0 energy, E

Question

In the reaction shown, the concentrations of both X and Y are reduced to half of their original values whilst keeping the total volume of the solution constant. X(aq) + Y(aq) → XY(aq) Simultaneously the temperature is increased from 298 K to 348 K. Which prediction is definitely true? A A smaller proportion of collisions between particles of X and particles of Y will be successful. B The average kinetic energy of particles of X and particles of Y will increase. C The rate of the reaction will be unaffected. D The frequency of collisions between particles of X and particles of Y will halve.

Question

A student investigated the chloride of a Period 3 element. This is what the student wrote down as a record. The compound was a white crystalline solid. It dissolved easily in water to give a solution of pH 12. When placed in a test-tube and heated in a roaring Bunsen flame, the compound melted after several minutes heating. What can be deduced from this record? A At least one of the recorded observations is incorrect. B The compound was magnesium chloride, MgCl 2. C The compound was phosphorus pentachloride, PCl 5. D The compound was sodium chloride, NaCl.

Question

The elements in Period 3 and their compounds show trends across the period from sodium to chlorine. Which row is correct? electronegativity acid / base behaviour of of the elements the oxides of the elements A decreases basic → amphoteric → acidic B decreases acidic → amphoteric → basic C increases basic → amphoteric → acidic D increases acidic → amphoteric → basic

Question

The table shows the melting points of SiO2 and P4O6. oxide SiO2 P4O6 melting point / K 1883 297 Which statement explains the difference between the melting points of SiO2 and P4O6? A The bonding of the oxides changes from ionic to covalent. B The metallic character of the elements decreases across Period 3. C The oxidation number of the element increases from Si to P. D The structure changes from giant molecular to simple molecular.

Question

Equal masses of CaCO3, Ca(NO3)2, BaCO3 and Ba(NO3)2 are thermally decomposed. The volume of gas produced in each experiment is measured under the same conditions. Which compound will produce the greatest volume of gas? A CaCO3 B Ca(NO3)2 C BaCO3 D Ba(NO3)2

Question

Which row gives correct comparisons between the solubilities of calcium hydroxide and barium hydroxide and the thermal stabilities of calcium carbonate and barium carbonate? solubility thermal stability calcium hydroxide barium hydroxide calcium carbonate barium carbonate A higher lower higher lower B higher lower lower higher C lower higher higher lower D lower higher lower higher

Question

Which statement relating to the elements in Group 17 and their compounds is correct? A Bromine will reduce KI to form iodine. B Iodide ions react to form a white precipitate when added to silver nitrate solution. C Bromide ions react to form a white precipitate when added to silver nitrate solution. D Chlorine reacts with hydrogen to form a colourless gas.

Question

An excess of chlorine was bubbled into 100 cm3 of hot 6.0 mol dm–3 sodium hydroxide. How many moles of sodium chloride would be produced in the reaction? A 0.30 B 0.50 C 0.60 D 0.72

Question

The product of the Contact process is Z. Which reaction or process leads to the formation of a gas that can neutralise an aqueous solution of Z? A atmospheric lightning B combustion of fuel in an internal combustion engine C the Haber process D thermal decomposition of Group 2 nitrates

Question

When ammonia, NH3, is dissolved in water, a small concentration of ammonium ions, NH4+, is formed. Which row is correct? number of change of the H–N–H electrons in one angle from ammonia ammonium ion to the ammonium ion A 8 decreases B 8 increases C 10 decreases D 10 increases

Question

In this question, alkenes and cyclic alkanes should be considered. How many structural isomers of C4H8 are there? A 3 B 4 C 5 D 6

Question

Which compound will decolourise Br2(aq)? A CH3CH2CH2CH2CH2CO2H B CH3CH2CH2CH2CH2CHO C CH3CHCHCH2CH2CH2OH D CH3CH2CH2CO2CH2CH3

Question

Alkenes react with aqueous hydrogen bromide. The reaction proceeds via an intermediate carbocation. The more stable the intermediate, the faster the reaction. Which sequence correctly shows an increase in the speed of reaction of the alkenes with hydrogen bromide? A ethene, propene, 2-methylpropene B 2-methylpropene, ethene, propene C propene, ethene, 2-methylpropene D propene, 2-methylpropene, ethene

Question

A reaction occurs when a sample of 1-chloropropane is heated under reflux with sodium hydroxide dissolved in ethanol. Which row is correct? type of reaction name of product A elimination propan-1-ol B elimination propene C substitution propan-1-ol D substitution propene

Question

The diagram shows the structures of three halogenoalkanes. P Q R CH3 H H CH3 C Br H C Br H C Cl CH3 H H P, Q and R can all be hydrolysed. Which row is correct? relative speed mechanism of hydrolysis of hydrolysis Q R P Q A fast slow SN1 SN2 B fast slow SN2 SN1 C slow fast SN1 SN2 D slow fast SN2 SN1

Question

A sample of 2.30 g of ethanol is mixed with an excess of aqueous acidified potassium dichromate(VI). The reaction mixture is boiled under reflux for one hour. The required organic product is then collected by distillation. The yield of product is 60.0%. Which mass of product is collected? A 1.32 g B 1.38 g C 1.80 g D 3.00 g

Question

The structure of tartaric acid is shown. tartaric acid OH O HO OH O OH Four moles of substance X react with one mole of tartaric acid. What could be substance X? A sodium B sodium carbonate C sodium hydrogencarbonate D sodium hydroxide

Question

Which compound gives both: ● an orange precipitate with 2,4-DNPH reagent ● and a yellow precipitate with alkaline I2(aq)? A ethanol B methanal C propanal D propanone

Question

A student suggests two uses of LiAl H4. LiAl H4 reaction 1 CH3 CH CH2 CH3 CH2 CH3 LiAl H4 reaction 2 CH3CO2H CH3CH2OH Which reactions would give the product shown? A both reactions B reaction 1 only C reaction 2 only D neither reaction

Question

Compound X contains a single ester group. X contains 27.6% by mass of oxygen. Which pair of products could be produced by the hydrolysis of X? A butan-1-ol and ethanoic acid B ethanol and propanoic acid C methanol and methanoic acid D propan-2-ol and butanoic acid

Question

What is the least number of carbon atoms in a non-cyclic alkane molecule that has a chiral centre? A 7 B 8 C 9 D 10

Question

A molecule of a polymer contains the sequence shown. H H H H H Cl H H H Cl H H C C C C C C C C C C C C H Cl Cl H H H Cl H H H H Cl Which monomer could produce this polymer by addition polymerisation? A CHCl =CHCl B CH2=CHCl C CH3CCl =CHCl D CH3CCl =CH2

Question

Compound Y is heated with a mild oxidising agent. One of the products of the reaction reacts with hydrogen cyanide forming 2-hydroxybutanenitrile. What is compound Y? A butan-1-ol B butan-2-ol C propan-1-ol D propan-2-ol

Question

The diagrams show the structures of lycopene and β-carotene. lycopene CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 β-carotene CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 When lycopene is converted into β-carotene, what is the gain or loss of hydrogen atoms per molecule? A 4 gained B 2 gained C no change D 2 lost

Question

Which diagram shows the infrared spectrum of a compound that contains both a C=O and an O–H group? A B 100 100 transmittance / % transmittance / % 50 50 0 0 3000 2000 1000 3000 2000 1000 –1 –1 wavenumber / cm wavenumber / cm C D 100 100 transmittance / % transmittance / % 50 50 0 0 3000 2000 1000 3000 2000 1000 –1 –1 wavenumber / cm wavenumber / cm bond functional group 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 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 at www.cambridgeinternational.org after the live examination series. 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 – – – – – – – – – – – Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge