Chemistry 0620/21 October/November 2023: question paper and mark scheme

Question

A gas is placed in a sealed container. The gas has a pressure of one atmosphere and a temperature of 50 °C. It is heated to 100 °C. Which row describes the cause of the pressure of the gas and the effect of increasing the temperature of the gas? the effect of increased cause of gas pressure temperature of the gas A collisions between collisions become gas particles less frequent B collisions between the average speed of gas particles the gas particles increases C collisions between gas collisions become particles and the container less frequent D collisions between gas the average speed of particles and the container the gas particles increases

Question

Four experiments, each containing a different acidic gas, are set up as shown. The dividing glass plates are removed at the same time. In which set of apparatus does the litmus turn red first? A B damp blue damp blue litmus paper litmus paper air air glass plate glass plate carbon dioxide, CO2 hydrogen chloride, HCl C D damp blue damp blue litmus paper litmus paper air air glass plate glass plate nitrogen dioxide, NO2 sulfur dioxide, SO2

Question

The Group I element potassium forms an ionic bond with the Group VII element fluorine. Which two ions are produced? A K+ and F+ B K+ and F– C K– and F– D K– and F+

Question

X and Y are atoms. ● X and Y have the same number of electron shells. ● X and Y have the same number of outer electrons. ● X and Y have different mass numbers. Which statements about X and Y are correct? 1 X and Y are isotopes. 2 X and Y have the same total number of electrons. 3 X and Y have the same chemical properties. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Lithium chloride is an ionic compound and silicon(IV) oxide is a covalent compound. Which statement about both compounds is correct? A They are not soluble in water. B They conduct electricity when melted. C They do not conduct electricity in solid form. D They have low melting points.

Question

Which equations are balanced? 1 Fe2O3 + 3CO → 2Fe + 3CO2 2 ZnCO3 + 2HCl → ZnCl 2 + CO2 + 2H2O 3 Mg(NO3)2 + NaOH → Mg(OH)2 + 2NaNO3 4 CaCO3 + H2SO4 → CaSO4 + H2O + CO2 A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Which row shows the formulae of sodium carbonate, zinc nitrate and ammonium sulfate? sodium carbonate zinc nitrate ammonium sulfate A Na2CO3 ZnNO3 (NH4)2SO4 B Na2CO3 Zn(NO3)2 (NH4)2SO4 C NaCO3 ZnNO3 (NH3)2SO4 D NaCO3 Zn(NO3)2 (NH3)2SO4

Question

Which statements about hydrogen and oxygen are correct? hydrogen and oxygen hydrogen and oxygen can can react to produce be made by the electrolysis of electrical energy dilute aqueous sodium chloride A B C D

Question

Graphite has a giant covalent structure. Which statements about graphite are correct? 1 Carbon atoms form four covalent bonds with neighbouring atoms. 2 There are delocalised electrons between layers of carbon atoms. 3 Graphite is a useful lubricant. 4 Graphite is a good conductor of electricity. A 1 and 2 B 1, 3 and 4 C 2, 3 and 4 D 3 and 4 only

Question

Which reaction pathway diagram represents an endothermic reaction? A B products products energy energy 'H = –24 kJ / mol 'H = +24 kJ / mol reactants reactants progress of reaction progress of reaction C D reactants reactants energy energy 'H = +24 kJ / mol 'H = –24 kJ / mol products products progress of reaction progress of reaction

Question

Hydrogen burns in oxygen. The equation for the reaction is shown. 2H2 + O2 → 2H2O The table shows the bond energies involved. bond energy bond in kJ / mol H–H 436 O=O 498 O–H 464 What is the energy given out during the reaction? A –3226 kJ / mol B –884 kJ / mol C –486 kJ / mol D –442 kJ / mol

Question

Which process involves a chemical change? A adding sodium to water B boiling water C dissolving sodium chloride in water D producing water from aqueous sodium chloride

Question

An experiment is carried out to find the rate of reaction between hydrochloric acid and zinc. Zn(s) + 2HCl (aq) → ZnCl 2(aq) + H2(g) The results of the experiment are shown. y-axis 0 0 time What is the label on the y-axis? A amount of ZnCl 2 produced B concentration of HCl C mass of Zn reacted D volume of H2 produced

Question

Hydrogen peroxide, H2O2, decomposes to form water and oxygen. 2H2O2(aq) → 2H2O(l) + O2(g) Manganese(IV) oxide catalyses the decomposition reaction. The reaction is investigated in four experiments. volume and concentration experiment conditions of hydrogen peroxide 1 12.5 cm3 of 1.0 mol / dm3 25 °C with manganese(IV) oxide powder added 2 12.5 cm3 of 2.0 mol / dm3 40 °C with manganese(IV) oxide powder added 3 25 cm3 of 1.0 mol / dm3 40 °C without manganese(IV) oxide powder 4 25 cm3 of 1.0 mol / dm3 40 °C with manganese(IV) oxide powder added All reactions go to completion and all measurements of gas volumes are at room temperature and pressure. Which statement is correct? A Experiment 1 produces less gas than experiment 4, but at the same rate. B Experiment 2 produces more gas than experiment 1, but at the same rate. C Experiment 2 and experiment 4 each produce the same volume of gas, but at different rates. D Experiment 3 and experiment 4 each produce the same volume of gas and at the same rate.

Question

Sulfuric acid is produced by the Contact process. Which row shows the typical conditions used in the process? pressure temperature catalyst / kPa / °C A iron 200 300 B iron 20 000 450 C vanadium(V) oxide 200 450 D vanadium(V) oxide 20 000 300

Question

Which equation shows the reduction of copper? A CuO + C → Cu + CO B 2CuS + 3O2 → 2CuO + 2SO2 C Cu(g) → Cu(l) D Cu(l) → Cu(s)

Question

Which statement about acids is correct? A A weak acid partially dissociates in aqueous solution. B An acid accepts protons when added to water. C Ethanoic acid acts as a strong acid when added to water. D Hydrochloric acid is a strong acid that ionises in water to form H– ions.

Question

Copper(II) sulfate is formed by reacting excess solid copper(II) carbonate with dilute sulfuric acid. Which processes are part of the preparation of solid copper(II) sulfate? 1 crystallisation 2 distillation 3 filtration 4 titration A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which type of reaction is represented by the equation shown? Pb2+(aq) + 2NO3–(aq) + 2Na+(aq) + 2I–(aq) → PbI2(s) + 2Na+(aq) + 2NO3–(aq) A addition B redox C neutralisation D precipitation

Question

Which compound is likely to be coloured? A KMnO4 B KNO3 C K2CO3 D K2SO4

Question

Which statements about the metal zinc are correct? 1 It is extracted from the ore bauxite. 2 It is used to galvanise steel. 3 It is used to make the alloy brass. 4 It reacts with dilute hydrochloric acid to produce hydrogen gas. A 1, 2 and 4 B 1, 3 and 4 C 2, 3 and 4 D 2 and 3 only

Question

The electronic configurations of four elements, P, Q, R and S, are shown. electronic element configuration P 2 Q 2,2 R 2,6 S 2,8 Which elements are unreactive monatomic gases? A P and Q B P and S C Q and R D S only

Question

Which row compares the strength of alloys with pure metals and explains the difference in strength? strength of an alloy explanation compared to a pure metal A weaker larger atoms slide more easily over smaller atoms B weaker larger atoms make it harder for layers to slide over one another C stronger larger atoms slide more easily over smaller atoms D stronger larger atoms make it harder for layers to slide over one another

Question

Zinc oxide reacts with carbon to produce zinc. Which equation represents this reaction? A 2ZnO + C → 2Zn + CO B 2ZnO + 2C → 2Zn + 2CO2 C ZnO + C → Zn + CO D ZnO + 2C → Zn + 2CO2

Question

When a piece of aluminium foil is added to dilute hydrochloric acid, no effervescence is seen. Which statement explains why no effervescence is seen? A Aluminium does not make a gas when it reacts with an acid. B Aluminium has a surface layer of aluminium oxide. C Aluminium is less reactive than hydrogen. D Aluminium only reacts with concentrated acid.

Question

Iron nails are stored in an airtight container. lid air iron nails The nails begin to rust after a few days. How can the rusting of the nails be prevented? A Leave the lid off. B Replace the air with argon. C Put the container in a warm place. D Seal the container in a bag.

Question

Four substances present in the blast furnace during iron extraction are listed. 1 calcium carbonate 2 carbon dioxide 3 carbon monoxide 4 iron(III) oxide Which substances are both a reactant and a product during the reactions occurring in the blast furnace? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Aluminium is extracted from purified bauxite by electrolysis. Which row shows the ionic half-equations for the reaction at each electrode? anode cathode A Al → Al 3+ + 3e– 2O2– + 4e– → O2 B Al 3+ + 3e– → Al 2O2– → O2 + 4e– C 2O2– + 4e– → O2 Al → Al 3+ + 3e– D 2O2– → O2 + 4e– Al 3+ + 3e– → Al

Question

Which test is used to show that a sample of water is pure? A Evaporate the water to see if any solids remain. B Heat the water to check its boiling point. C Test with anhydrous cobalt(II) chloride. D Use universal indicator paper to check its pH.

Question

Catalytic converters in car exhausts change polluting gases into non-polluting gases. Which statements about oxides of nitrogen and car engines are correct? 1 The nitrogen in oxides of nitrogen comes from compounds in gasoline. 2 The oxygen in oxides of nitrogen comes from the air in the car engine. 3 Catalytic converters convert oxides of nitrogen into nitrogen. A 1 and 2 B 2 and 3 C 2 only D 3 only

Question

The structures of two molecules, X and Y, are shown. X Y H H H C H H H H H H H H H H H C C C C C C H H C C C C C C H H H H H H H H H H Which row describes X and Y? structural belong to same isomers homologous series A no no B no yes C yes no D yes yes

Question

What is the structure of butanoic acid? A B H H H H H H H H C C C O H H C C C C O H H H H H H H H C D H H O H H H O H C C C O H H C C C C O H H H H H H

Question

When a mixture of methane and chlorine is exposed to ultraviolet light, a reaction takes place. Which statements about this reaction are correct? 1 It is an addition reaction. 2 The ultraviolet light provides the activation energy. 3 An equation for the reaction is CH4 + Cl 2 → CH2Cl 2 + H2. 4 CH3Cl is made in the reaction. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Esters are formed when a carboxylic acid reacts with an alcohol. What is the catalyst for this reaction? A aqueous potassium manganate(VII) B iron C sulfuric acid D vanadium(V) oxide

Question

The diagram shows part of a polymer. H H H H H H H H C C C C C C C C H H H H H H H H Which diagram shows the monomer from which this polymer is made? A B C D H H H H H H H H C H H C C H C C H C C O H H H H H H H H

Question

Nylon and PET are polymers. Which statements about these polymers are correct? 1 They are both condensation polymers. 2 HOCH2CH2CH2OH could be a monomer for both polymers. 3 The complete combustion of both polymers gives two products only. A 1 and 2 B 1 and 3 C 1 only D 2 and 3

Question

Ethane is used as a fuel. Which equation shows the complete combustion of ethane? A 2C2H6 + 7O2 → 4CO2 + 6H2O B 2C2H6 + 5O2 → 4CO + 6H2O C C2H4 + 3O2 → 2CO2 + 2H2O D C2H4 + 2O2 → 2CO + 2H2O

Question

The painkiller paracetamol is synthesised from 4-aminophenol. Chromatography is done on an impure sample of paracetamol. The results are shown. The diagram is not drawn to scale. solvent front key 4.40 cm 3.50 cm S = impure sample of paracetamol 2.60 cm P = pure paracetamol 1.70 cm baseline S P The sample of paracetamol is contaminated with 4-aminophenol only. What is the Rf value of 4-aminophenol? A 0.49 B 0.65 C 0.74 D 1.35

Question

The equation for the reaction of aqueous calcium nitrate and aqueous sodium hydroxide is shown. Ca(NO3)2(aq) + 2NaOH(aq) → Ca(OH)2(s) + 2NaNO3(aq) Which process is used to remove calcium hydroxide from the mixture? A chromatography B crystallisation C distillation D filtration

Question

The results of two tests on aqueous compound X are given. test result warm with aluminium foil and ammonia is produced aqueous sodium hydroxide aqueous sodium hydroxide brown precipitate What is X? A iron(III) nitrate B iron(II) nitrate C iron(III) sulfate D iron(II) sulfate The Periodic Table of Elements Group I II III IV V VI VII VIII 1 2 H He hydrogen helium Key 1 4 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 7 9 relative atomic mass 11 12 14 16 19 20 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 24 27 28 31 32 35.5 40 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 40 45 48 51 52 55 56 59 59 64 65 70 73 75 79 80 84 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 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 16 85 88 89 91 93 96 – 101 103 106 108 112 115 119 122 128 127 131 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 133 137 178 181 184 186 190 192 195 197 201 204 207 209 – – – 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 139 140 141 144 – 150 152 157 159 163 165 167 169 173 175 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 – 232 231 238 – – – – – – – – – – – The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.).