Chemistry 9701/12 February/March 2024: question paper and mark scheme

Question

Which species contains the same number of neutrons as 146 C and the same number of electrons + as 23 11Na ? 17 16 20 16 2 – A 9F B 7 N3 – C 10 Ne D 8O

Question

Which process has the largest enthalpy change per mole? A Al 3+(g) → Al 4+(g) + e– B P5+(g) → P6+(g) + e– C S6+(g) → S7+(g) + e– D Si4+(g) → Si5+(g) + e–

Question

Which sodium compound contains 74.2% by mass of sodium? A sodium carbonate B sodium chloride C sodium hydroxide D sodium oxide

Question

What is the maximum volume of sulfur dioxide gas measured at room conditions produced from burning 100 dm3 of diesel fuel containing 0.8346 g of sulfur? A 291 cm3 B 312 cm3 C 582 cm3 D 624 cm3

Question

Which row shows the correct number of covalent bonds in a molecule of methylpropene? total number of sigma (σ) total number of pi (π) bonds in the molecule bonds in the molecule A 10 1 B 10 2 C 11 1 D 11 2

Question

Aluminium chloride exists as Al 2Cl 6 molecules at room temperature. When heated to a high temperature, Al Cl 3 molecules are formed. What are the arrangements of the bonding pairs of electrons around the aluminium atom in the two forms of aluminium chloride? Al Cl 3 Al 2Cl 6 A planar planar B planar tetrahedral C tetrahedral tetrahedral D tetrahedral octahedral

Question

The table shows the physical properties of four substances. Which substance has a giant covalent structure? electrical electrical electrical melting point boiling point conductivity conductivity conductivity / °C / °C of aqueous of solid of liquid solution A –119 39 poor poor insoluble B –115 –85 poor poor good C 993 1695 poor good good D 1160 2230 poor poor insoluble

Question

At room temperature and pressure, H2O is a liquid and H2S is a gas. What is the reason for this difference of state? A O has higher first and second ionisation energies than S. B The covalent bond between O and H is stronger than the covalent bond between S and H. C There is significant hydrogen bonding between H2O molecules but not between H2S molecules. D The instantaneous dipole-induced dipole forces between H2O molecules are stronger than the instantaneous dipole-induced dipole forces between H2S molecules.

Question

The enthalpy change for a reaction can be calculated from values of: ● enthalpies of formation, ● enthalpies of combustion, ● bond energies, E. The enthalpy change of the reaction given = . 2C2H6(g) + 3O2(g) → 2CH4(g) + 2CO2(g) + 2H2O(l) Which expression could be used to calculate ? A (C2H6(g)) B 2 (C2H6(g)) – 2 (CH4(g)) C E(C–C) + 2E(C–H) – 4E(C=O) – 4E(H–O) D (CH4(g)) + (CO2(g)) + (H2O(l)) – (C2H6(g))

Question

Which reaction has an enthalpy change equal to the standard enthalpy change of formation of propane? A 3C(g) + 4H2(g) → C3H8(g) B 3C(g) + 8H(g) → C3H8(g) C 3C(s) + 4H2(g) → C3H8(g) D 3C(s) + 4H2(g) → C3H8(l)

Question

One of the reactions in the rechargeable lead / acid battery is shown. Pb(s) + PbO2(s) + 4H+(aq) + 2SO42–(aq) → 2PbSO4(s) + 2H2O(l) Which statement about this reaction is correct? A Lead is both oxidised and reduced. B Lead is neither oxidised nor reduced. C Lead is oxidised only. D Lead is reduced only.

Question

KMnO4 is an oxidising agent. Its reaction with Fe2+ is shown in the following ionic equation. ...X...MnO4– + ……Fe2+ + ……H+ → ……Mn2+ + ...Y...Fe3+ + ……H2O What are X and Y when the equation is balanced? X Y A 1 1 B 1 3 C 1 5 D 5 1

Question

Nitrogen and hydrogen are mixed in a reaction vessel. The reaction reaches equilibrium giving a mixture of nitrogen, hydrogen and ammonia gases. N2 + 3H2 2NH3 The mixture of gases present at equilibrium at a total pressure of 300 atm is shown. number of mol gas in mixture nitrogen 180 hydrogen 590 ammonia 160 What is the equilibrium constant, Kp, for the forward reaction? A 6.65 × 10–6 atm–2 B 7.13 × 10–5 atm–2 C 0.599 atm–2 D 1.50 × 105 atm2

Question

A mixture of hydrogen gas and iodine gas is placed in a reaction vessel of volume V at temperature T. The reaction H2 + I2 2HI is allowed to come to equilibrium. All substances remain in the gaseous state. Argon gas is then pumped into the reaction vessel. The temperature in the vessel is maintained at T. How are the rate of the forward reaction and the partial pressure of HI at equilibrium affected? rate of partial pressure of forward reaction HI at equilibrium A increased increased B increased unaffected C unaffected increased D unaffected unaffected

Question

Two experiments are carried out to study the reaction between zinc and sulfuric acid. experiment 1 Small lumps of zinc are added to excess dilute sulfuric acid. experiment 2 The reaction is carried out at a lower temperature and with one other change. Both experiments produce the same total volume of gas and are completed in the same time. What is the second change made in experiment 2? A A catalyst is added. B A greater mass of zinc is added. C A greater volume of sulfuric acid is added. D Larger lumps of zinc are used.

Question

The relative magnitude of the property X of five elements is shown. P, Q, R, S and T are all in Period 3 and have consecutive atomic numbers. The letters are not the actual chemical symbols of the elements. R Q P X S T atomic number Which row is correct for property X and element R? property X element R A electrical conductivity Al B electronegativity Si C melting point Al D second ionisation energy Si

Question

Element X is in Period 3. Element X reacts with oxygen to produce a solid, Y. When solid Y is added to water, a solution with a pH of less than 7 is produced. What is the identity of element X? A sodium B silicon C phosphorus D sulfur

Question

This question refers to isolated gaseous species. The species F–, Ne and Na+ are isoelectronic. This means they have the same number of electrons. In which order do their radii increase? smallest largest A Na+ F– Ne B F– Ne Na+ C Na+ Ne F– D Ne F– Na+

Question

Separate samples of magnesium and calcium are added to an excess of dilute sulfuric acid. The observations are summarised in the table. metal observations magnesium vigorous reaction, bubbles of gas produced, magnesium completely dissolves calcium vigorous reaction initially, bubbles of gas produced, reaction soon stops and leaves most of the calcium unreacted Which statement explains the difference in these observations? A Calcium is a better oxidising agent than magnesium. B Calcium is a better reducing agent than magnesium. C Magnesium is a more reactive metal with all dilute acids than calcium. D Magnesium sulfate is more soluble than calcium sulfate.

Question

Dolomite is a double carbonate, CaMg(CO3)2, and can be used instead of calcium carbonate for treating acidic soils. The three statements all refer to the agricultural use of these carbonates. 1 Dolomite and calcium carbonate are both less soluble than Ca(OH)2. 2 One mole of dolomite has the same neutralising effect as one mole of calcium carbonate. 3 Dolomite and calcium carbonate both increase the pH of acidic soils. Which statements are correct? A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

Question

This question is about two salts, NaI and NaCl. The two solid salts are separately added to warm concentrated H2SO4 and the results noted. Aqueous solutions of the two salts are separately added to AgNO 3(aq) and then concentrated NH3(aq) is added and the results noted. Which row is correct? identity of one product formed observation after AgNO3(aq) salt with concentrated H2SO4 and NH3(aq) are added A NaCl Cl 2 colourless solution B NaCl H2S white precipitate C NaI H2S yellow precipitate D NaI I2 colourless solution

Question

The diagram shows the process of adding calcium nitrate and strontium nitrate to separate boiling tubes and heating them. Identical conditions are used. Ca(NO3)2 water containing Sr(NO3)2 water containing universal indicator universal indicator heat heat As the reactions proceed, the water containing universal indicator changes colour. Which row describes the colour change and identifies the nitrate that causes the quickest colour change? colour change of nitrate that causes the universal indicator quickest colour change A green to blue Ca(NO3)2 B green to blue Sr(NO3)2 C green to red Ca(NO3)2 D green to red Sr(NO3)2

Question

The equations for three reactions involving chlorine or its compounds are listed. 1 2KCl O3 → 2KCl + 3O2 2 4KCl O3 → 3KCl O4 + KCl 3 6KOH + 3Cl 2 → 3H2O + 5KCl + KCl O3 Which statement about these equations is correct? A Equation 1 describes the formation of a compound used to kill bacteria in drinking water. B Equation 1 does not represent a redox reaction. C Equation 2 describes the formation of potassium chlorate(IV). D Equations 2 and 3 both represent disproportionation reactions.

Question

Nitrogen monoxide, NO, is a primary pollutant produced by petrol engines and is found in their exhaust gases. Which reaction occurs in a catalytic converter and decreases the emission of nitrogen monoxide? A NO(g) + CO(g) → NO2(g) + C(s) B NO(g) + CO2(g) → NO2(g) + CO(g) C 2NO(g) + 2CO(g) → N2(g) + 2CO2(g) D 2NO(g) + CO2(g) → 2NO2(g) + C(s)

Question

The diagram shows the structure of the naturally occurring molecule cholesterol. cholesterol H 3C CH3 CH3 HO Student X stated that the 17 carbon atoms in the 4 rings all lie in the same plane. Student Y stated that this molecule displays cis/trans isomerism at the C=C double bond. Which students are correct? A both student X and student Y B neither student X nor student Y C student X only D student Y only

Question

The drug cortisone has the formula shown. cortisone OH OH O O O In addition to those chiral centres marked by an asterisk (*), how many other chiral centres are present in the cortisone molecule? A 0 B 1 C 2 D 3

Question

But-2-ene reacts with cold dilute acidified KMnO4 to give product X. But-2-ene reacts with hot concentrated acidified KMnO4 to give product Y. Which statement about product X and product Y is correct? A Both product X and product Y will react with 2,4-dinitrophenylhydrazine. B Neither product X nor product Y will react with 2,4-dinitrophenylhydrazine. C Product X will react with 2,4-dinitrophenylhydrazine, product Y will not. D Product Y will react with 2,4-dinitrophenylhydrazine, product X will not.

Question

A sequence of reactions takes place. The major product is compound Z. concentrated LiAl H4 H2SO4 propanoic acid compound X compound Y pass vapour with steam over H3PO4 compound Z What is compound Z? A propanone B propene C propan-1-ol D propan-2-ol

Question

Which statement is correct? A Bromoethane reacts with NaOH(aq) to form ethene as a major product. B 1-chlorobutane reacts more rapidly than 1-bromobutane with NaOH(aq) at the same temperature. C Hydrolysis of (C2H5)3CBr occurs mostly by the SN2 mechanism. D The CH3CH2CH2CH2+ ion is less stable than the (CH3)3C+ ion.

Question

In the hydrolysis of bromoethane by aqueous NaOH, what is the nature of the attacking group and of the leaving group? attacking group leaving group A electrophile electrophile B electrophile nucleophile C nucleophile electrophile D nucleophile nucleophile

Question

X is an organic compound containing the elements carbon, hydrogen and oxygen only. The table shows the observations made from three chemical tests carried out on X. reagent added observation Na(s) effervescence Na2CO3(s) effervescence hot H+ / Cr2O72–(aq) remains orange What is a possible structure of X? A B C D OH O O O HO O OH OH OH OH

Question

How many moles of oxygen gas are needed for the complete combustion of 1 mol of (CH3)3COH? A 6 B 6.5 C 12 D 13

Question

In which pair will each compound give a different visible result with alkaline I2(aq)? A CH3CH2OH and CH3CHO B CH3CHO and CH3COCH3 C CH3COOH and C2H5COC2H5 D CH3CH2OH and C2H5CHO

Question

Which reagent gives a positive result with propanone? A alkaline I2(aq) B aqueous bromine C Fehling’s reagent D Tollens’ reagent

Question

Esters can be hydrolysed with an aqueous alkali or an aqueous acid to form two products. The table compares the two methods. Which row is correct? aqueous alkali aqueous acid A complete conversion to forms an equilibrium mixture with a salt and an organic acid an organic acid and an alcohol B forms an equilibrium mixture complete conversion to with a salt and an organic acid a salt and an alcohol C complete conversion to forms an equilibrium mixture with a salt and an alcohol an organic acid and an alcohol D complete conversion to complete conversion to a salt and an alcohol an organic acid and an alcohol

Question

Structural isomerism only should be considered when answering this question. How many compounds with molecular formula C5H11Br are primary halogenoalkanes? A 4 B 5 C 7 D 8

Question

Compound Z is formed by the reaction scheme shown. warm with reflux with CH3CH2Br compound X compound Z KCN in ethanol dilute HCl What is the formula of compound Z? A CH3CH2Cl B CH3CH2CN C CH3COOH D CH3CH2COOH

Question

Hydroxyethanal, HOCH2CHO, is heated under reflux with an excess of acidified K2Cr2O7 until no further oxidation takes place. What is the skeletal formula of the organic product? A B C D O O OH O HO HO OH OH OH OH O O O O

Question

The formula shows the repeat unit of an addition polymer. –CH(CH3)CH(CH2CH3)– What is the correct name of the monomer from which this polymer is made? A 1-methyl-2-ethylethene B 1-ethylprop-1-ene C pent-2-ene D pent-1-ene

Question

The infrared spectrum of a compound is shown. 100 transmittance / % 50 0 4000 3000 2000 1500 1000 500 –1 wavenumber / cm characteristic infrared absorption range bond functional groups containing the bond (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 Which functional group could the compound contain? A alcohol B carboxylic acid C ester D nitrile 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 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 – – – – – – – – – – –