Chemistry 9701/12 February/March 2025: question paper and mark scheme

Question

A Boltzmann distribution for a sample of a reacting gas at a constant temperature is shown. The activation energy, EA, for the reaction is marked. Point × shows the number of particles whose energy is equal to the activation energy. The temperature of the sample of gas is decreased. The shape of the distribution curve changes. Which point could show the number of particles whose energy is the same as the activation energy at the new temperature? number of B particles A C D EA energy

Question

Crystals of copper(II) nitrate are prepared by adding an excess of malachite to nitric acid. The formula of malachite is Cu(OH)2•CuCO3. (Mr = 221.0) 12.0 g of malachite is added to 30.0 cm3 of 1.50 mol dm–3 nitric acid. Which mass of malachite is left unreacted when the reaction is complete? A 2.05 g B 2.49 g C 7.03 g D 9.51 g

Question

X and Y are elements from the same group of the Periodic Table. The 5th to 9th ionisation energies for X and Y are shown. ionisation energy / kJ mol–1 5th 6th 7th 8th 9th element X 11 020 15 160 17 870 92 040 106 437 element Y 6 540 9 360 11 020 33 360 38 600 Which row identifies elements X and Y? element X element Y A argon neon B chlorine fluorine C fluorine chlorine D neon argon

Question

An ion with a charge of 2– contains 10 electrons and 14 neutrons. What is its nucleon number? A 14 B 22 C 24 D 26

Question

The structure of the hormone histamine is shown. histamine H H H H N C xN N yC C C z H C H H H H Which row contains the bond angles x, y and z in histamine in the correct order from the smallest to the largest? smallest largest bond angle bond angle A x y z B y x z C y z x D z y x

Question

When an organic acid reacts with an alcohol, a reversible reaction takes place producing an ester and water. 0.40 mol of an organic acid and 0.30 mol of an alcohol are mixed and allowed to stand at 25 °C until equilibrium is reached. At equilibrium, 0.20 mol of ester is produced. What is the value of the equilibrium constant, Kc, under the conditions used? A 0.33 B 0.50 C 2.0 D 10

Question

Information about two substances is given. substance electrical conductivity effect of adding to water melting point / K P good when solid reacts vigorously to 454 and when molten produce an alkaline solution Q does not conduct reacts vigorously to 317 in any state produce an acidic solution Which row describes the structure and bonding in substances P and Q? P Q A giant metallic simple molecular B simple molecular giant metallic C giant ionic simple molecular D giant metallic giant ionic

Question

An excess of zinc reacts with x cm3 of 2.00 mol dm–3 hydrochloric acid. The gas produced is dried and collected. The gas occupies 1.534 dm3 at 101 000 Pa and 293 K. The gas produced behaves as an ideal gas. What is the value of x? A 31.8 cm3 B 34.7 cm3 C 63.6 cm3 D 69.4 cm3

Question

An aqueous solution of hydrogen peroxide is placed in a flask and decomposes, as shown. 2H2O2(aq) → 2H2O(l) + O2(g) The total volume of oxygen gas evolved is 180 cm3 after 90 seconds, measured under room conditions. The rate of the reaction is calculated using the equation shown. change in moles of H2O2 rate = time What is the average rate of the reaction, measured in mol min–1, over the duration of the experiment? A 8.33 × 10–5 B 1.67 × 10–4 C 0.0050 D 0.010

Question

Methanol is manufactured by reacting carbon dioxide and hydrogen together. CO2(g) + 3H2(g) CH3OH(g) + H2O(g) ΔH = – 49 kJ mol–1 What increases the equilibrium yield of methanol in this process? A increasing the pressure B adding an excess of steam C adding a catalyst D increasing the temperature

Question

The equation for a reaction of KCl O3 is shown. 4KCl O3 → KCl + 3KCl O4 Which row is correct? disproportionation oxidation number reaction of chlorine in KCl O4 A yes +4 B yes +7 C no +4 D no +7

Question

A student mixes 25.0 cm3 of 0.100 mol dm–3 sodium hydroxide solution with 25.0 cm3 of 0.100 mol dm–3 hydrochloric acid and the student records a temperature rise of 2.50 °C. What is the enthalpy change of the reaction per mole of NaOH? A –209 kJ mol–1 B –104.5 kJ mol–1 C –209 J mol–1 D –522.5 J mol–1

Question

Carbon monoxide and methanol can react together to form ethanoic acid. CO(g) + CH3OH(l) CH3CO2H(l) Standard enthalpy changes of combustion are given in the table. standard enthalpy change compound of combustion, CO –283.0 kJ mol–1 CH3OH –726.0 kJ mol–1 CH3CO2H –874.1 kJ mol–1 What is the value for for the reaction between carbon monoxide and methanol? A –1883.1 kJ mol–1 B –134.9 kJ mol–1 C +134.9 kJ mol–1 D +1883.1 kJ mol–1

Question

Copper reacts with nitric acid under certain conditions. The products are copper(II) nitrate, water and an oxide of nitrogen. 3 mol of copper reacts with exactly 8 mol of nitric acid. What is the oxidation state of nitrogen in the oxide produced? A +1 B +2 C +3 D +4

Question

All the reactants and products of an exothermic reaction are gaseous. Which statement about this reaction is correct? A The total bond energy of the products is less than the total bond energy of the reactants, and ΔH for the reaction is negative. B The total bond energy of the products is less than the total bond energy of the reactants, and ΔH for the reaction is positive. C The total bond energy of the products is more than the total bond energy of the reactants, and ΔH for the reaction is negative. D The total bond energy of the products is more than the total bond energy of the reactants, and ΔH for the reaction is positive.

Question

Propene, hydrogen cyanide and carbon dioxide each contain π bonds. Which molecules contain two π bonds? A carbon dioxide and hydrogen cyanide B carbon dioxide and propene C hydrogen cyanide and propene D hydrogen cyanide only

Question

Q, R and S are consecutive elements in Period 3 of the Periodic Table. Element R has the highest first ionisation energy and the lowest melting point of these three elements. What are the identities of Q, R and S? Q R S A Na Mg Al B Mg Al Si C Al Si P D Si P S

Question

A reaction scheme for a Group 2 metal, M, is shown. reacts with reacts with reacts with oxygen water sulfuric acid M X Y Z Which row is correct as M descends Group 2 from Mg to Ba? solubility of Y solubility of Z in water in water A decreases decreases B decreases increases C increases decreases D increases increases

Question

U, V and W represent different halogens. The table shows the results of nine experiments in which aqueous solutions of U2, V2 and W 2 were separately added to separate aqueous solutions containing U–, V – and W – ions. U–(aq) V –(aq) W –(aq) U2(aq) no reaction no reaction no reaction V2(aq) U2 formed no reaction W 2 formed W2(aq) U2 formed no reaction no reaction Which row contains the ions U–, V – and W – in order of their decreasing strength as reducing agents? strongest weakest A U– V– W– B U– W– V– C V– W– U– D W– U– V–

Question

J is either MgCl 2 or Al Cl 3. K is either SiO2 or SiCl 4. add drops of aqueous white add an excess of aqueous precipitate J(aq) sodium hydroxide precipitate sodium hydroxide dissolves add water misty white fumes and a K white precipitate in a solution with pH less than 7 Which row is correct? identity of J identity of K A Al Cl 3 SiCl 4 B Al Cl 3 SiO2 C MgCl 2 SiCl 4 D MgCl 2 SiO2

Question

River water in an agricultural area contains NH4+, CO32–, HCO3–, Cl − and NO3– ions. This water is treated by adding a calculated quantity of calcium hydroxide. What is precipitated from the river water when calcium hydroxide is added? A CaCl 2 B CaCO3 C Ca(NO3)2 D NH4OH

Question

Four atmospheric pollutants are listed. 1 nitrogen oxides 2 carbon monoxide 3 unburnt hydrocarbons 4 sulfur dioxide Which pair of pollutants react to form peroxyacetyl nitrate, PAN? A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which graph correctly describes a trend found in Group 17? [X represents a halogen atom.] A B bond strength of length van der Waals’ in X2 forces Cl 2 Br2 I2 Cl 2 Br2 I2 C D boiling bond point energy of X2 of HX Cl 2 Br2 I2 HCl HBr HI

Question

Gas M is produced when NH4Cl (aq) is heated with CaO(s). Which row is correct? type of reaction identity of M A acid–base N2 B redox NH3 C acid–base NH3 D redox N2

Question

Two nitrates decompose on heating according to the equations shown. 2Pb(NO3)2(s) → 2PbO(s) + 4NO2(g) + O2(g) 2NH4NO3(s) → 2N2(g) + O2(g) + 4H2O(l) One mole of each nitrate is heated separately. The gas produced in each reaction is bubbled through NaOH(aq). The volume of any gas that does not react with NaOH(aq) is then collected and measured. Which nitrate: ● shows the greater percentage loss in mass ● produces the greater volume of gas collected? greater percentage greater volume loss of mass of gas collected A NH4NO3 NH4NO3 B NH4NO3 Pb(NO3)2 C Pb(NO3)2 NH4NO3 D Pb(NO3)2 Pb(NO3)2

Question

Organic compound X has the empirical formula C2H4O. Compound X is reduced by LiAl H4, but not by NaBH4. What is compound X? A ethanoic acid B ethanal C butan-1-ol D butanoic acid

Question

What is the mechanism of the reaction of hydrogen cyanide with propanone? A electrophilic addition B electrophilic substitution C nucleophilic addition D nucleophilic substitution

Question

Which compound may be synthesised from an alkene, with formula C4H8, by an addition reaction? A 1,1-dibromobutane B 1,2-dibromobutane C 1,3-dibromobutane D 1,3-dibromomethylpropane

Question

The structure of compound G is shown. C N CH2 C C OCH3 O Compound G undergoes addition polymerisation. Which diagram shows the repeat unit of the polymer formed? A B C D C N H C N C N CH C C CH C C N CH2 C C CH2 O CO2CH3 CO2CH3 CO2CH3

Question

Compound T is tested with three reagents and gives the results shown. reagent result 2,4-DNPH orange precipitate Fehling’s solution no reaction acidified K2Cr2O7 no reaction What is compound T? A (CH3)2CHCHO B (CH3)2CHCH2OH C CH3CH(OH)COCH3 D (CH3)2CHCOCH3

Question

Reagent X is added separately to 2-methylbutan-1-ol and 3-methylbutan-2-ol. The visible results are different. What is reagent X? A Na(s) B alkaline I2(aq) C PCl 5 D acidified KMnO4

Question

Compound Y is hydrolysed by warm aqueous silver nitrate to form a precipitate that is soluble in dilute aqueous ammonia. Compound Y undergoes an elimination reaction to form an alkene. What is the skeletal formula of compound Y? A B C D Br I Cl Cl

Question

Propan-2-ol can be converted into 2-chloropropane using reagent M followed by reagent N. Which row is correct? reagent M reagent N A concentrated NaOH Cl 2 B concentrated H2SO4 Cl 2 C concentrated H3PO4 HCl D concentrated NaOH HCl

Question

Skeletal formulae of four organic compounds are shown. O O O N O O 1 2 3 4 Which two compounds when separately heated with dilute sulfuric acid produce propanoic acid as one of the products? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 35 1-chloro-2-methylpropane and 2-bromo-2-methylbutane react separately with aqueous silver nitrate in ethanol. Both reactions proceed via nucleophilic substitution and a precipitate is formed. The time taken for 1-chloro-2-methylpropane to form a precipitate is T1. The time taken for 2-bromo-2-methylbutane to form a precipitate is T2. Which row is correct? main reaction time taken for compound mechanism precipitate to appear A 1-chloro-2-methylpropane SN1 T2 > T1 B 1-chloro-2-methylpropane SN2 T1 > T2 C 2-bromo-2-methylbutane S N1 T2 > T1 D 2-bromo-2-methylbutane S N2 T1 > T2

Question

In the question paper above.

Question

The diagram shows the structure of progesterone. progesterone O O Which statement about progesterone is correct? A One molecule contains four chiral carbon atoms only; the molecular formula is C19H26O2. B One molecule contains four chiral carbon atoms only; the molecular formula is C21H30O2. C One molecule contains six chiral carbon atoms; the molecular formula is C19H26O2. D One molecule contains six chiral carbon atoms; the molecular formula is C21H30O2.

Question

A molecule of hexane can be cracked in a number of different ways. Three compounds are listed. 1 C3H8 2 C4H8 3 C5H12 Which compounds are found in the mixture of products from the cracking of hexane molecules? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

The diagrams show the structures of two isomeric dicarboxylic acids, X and Y. O O O HO HO OH C H C C C C C C H C H H OH O X Y X can be reduced to compound P with empirical formula C2H5O. Y can be reduced to compound Q, also with empirical formula C2H5O. Which statement is correct? A X is a cis isomer; compound P and compound Q are identical. B X is a cis isomer; compound P and compound Q are isomers of each other. C X is a trans isomer; compound P and compound Q are identical. D X is a trans isomer; compound P and compound Q are isomers of each other.

Question

What is the total number of sp3 hybridised atomic orbitals used in the bonding of but-2-ene? A 2 B 4 C 6 D 8

Question

Compound L contains carbon atoms. It is analysed in a mass spectrometer. The table shows the relative abundance of the only two peaks recorded with m / e greater than 127. m/e relative abundance 128 50 129 5.5 How many carbon atoms are present in one molecule of compound L? A 5 B 7 C 8 D 10 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 138.9 140.1 140.9 144.2 – 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 – – – – – – – – – – –