Chemistry 0620/21 October/November 2022: question paper and mark scheme

Question

The diagram shows the changes of state between a solid, a liquid and a gas. 1 2 solid liquid gas 3 4 In which changes of state is energy being given out? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

A coloured dye is separated by chromatography. One component of the dye moves a distance of 13 cm and has an Rf value of 0.86. Which distance did the solvent front move? A 6.6 cm B 11.9 cm C 15.1 cm D 21.6 cm

Question

A mixture contains salt, sand and sulfur. Salt dissolves in water but not in xylene. Sulfur dissolves in xylene but not in water. Sand does not dissolve in water or xylene. What is the order of the processes used to separate the salt, the sand and the sulfur from the mixture? A add water → filter → add xylene to the filtrate → filter B add water → filter → add xylene to the residue → filter C add xylene → filter → add water to the filtrate → filter D add xylene → filter → add xylene to the residue → filter

Question

Which statements about isotopes of the same element are correct? 1 They are atoms which have the same chemical properties because they have the same number of electrons in their outer shell. 2 They are atoms which have the same number of electrons and neutrons but different numbers of protons. 3 They are atoms which have the same number of electrons and protons but different numbers of neutrons. A 1 and 2 B 1 and 3 C 2 only D 3 only

Question

Which type of structure and bonding is present in an element that is malleable and conducts electricity? A covalent molecular B ionic lattice C covalent macromolecular D metallic lattice

Question

Which statements about potassium bromide are correct? 1 It has a high melting point. 2 It dissolves in water. 3 It conducts electricity when solid. A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

Question

Which substance has a similar structure to silicon(IV) oxide? A carbon dioxide B diamond C graphite D sodium oxide

Question

Caffeine is a stimulant found in coffee. O CH3 H 3C C N N C C H C C N O N CH3 caffeine Which formula represents caffeine? A C7H10N4O2 B C8H10N3O2 C C8H10N4O2 D C8H11N4O2

Question

4.55 g of zinc is reacted with 50 cm3 of 2.25 mol / dm3 dilute hydrochloric acid. The equation for the reaction is shown. Zn + 2HCl → ZnCl 2 + H2 Which volume of hydrogen gas, at room temperature and pressure, is produced in the reaction? A 1.35 dm3 B 1.67 dm3 C 2.70 dm3 D 3.34 dm3

Question

In the electrolysis diagram, oxidation is occurring at electrode 1 and reduction at electrode 2. battery electrode 1 electrode 2 electrolyte Which row shows the directions of movement of the electrons in the external circuit and of the positive ions in the electrolyte? direction of movement of direction of movement of electrons in external circuit positive ions in electrolyte A 1→2 1→2 B 1→2 2→1 C 2→1 1→2 D 2→1 2→1

Question

When an acid is added to an alkali, the temperature of the reaction mixture rises. Which words describe this reaction? A decomposition and endothermic B decomposition and exothermic C neutralisation and endothermic D neutralisation and exothermic

Question

Some properties of four fuels are shown. Which fuel is a gas at room temperature and makes two products when it burns in a plentiful supply of air? melting point boiling point fuel formula / °C / °C A hydrogen H2 –259 –253 B methane CH4 –182 –164 C octane C8H18 –57 126 D wax C31H64 60 400

Question

Ethene can undergo complete combustion, as shown. H H C C + 3O O 2O C O + 2H O H H H Some bond energies are given in the table. bond energy bond in kJ / mol C=C 612 C–H 412 O–H 463 O=O 496 The energy change of the reaction is –1408 kJ / mol. What is the bond energy of the C=O bond in CO2? A 454 kJ / mol B 673 kJ / mol C 826 kJ / mol D 1619 kJ / mol

Question

A student adds excess zinc to dilute hydrochloric acid at 25 °C. The hydrogen gas produced is collected and measured at room temperature and pressure. The results are plotted and labelled as curve X on the graph. The experiment is repeated at 50 °C with all other conditions remaining the same. Which graph shows the results at 50 °C? A B volume of X hydrogen gas C D 0 0 time

Question

Dinitrogen tetroxide, N2O4, is converted into nitrogen dioxide, NO2, in a reversible reaction. N2O4(g) 2NO2(g) The forward reaction is endothermic. Which conditions give the highest equilibrium yield of nitrogen dioxide? pressure temperature / atmospheres A 2 high B 2 low C 50 high D 50 low

Question

When magnesium is heated with zinc oxide a reaction occurs. The equation is shown. Mg + ZnO → MgO + Zn Which substance is oxidised? A magnesium B magnesium oxide C zinc D zinc oxide

Question

The diagram shows an experiment. aqueous P tap solid Q A small volume of aqueous P is poured on to solid Q and the tap of the funnel closed. Which pairs of substances cause the syringe to fill with gas? HNO3 HCl H2SO4 and and and Mg Cu Na2CO3 A B C D

Question

Ethanoic acid reacts with water to produce an acidic solution. Which row describes the roles of ethanoic acid and water in this reaction? ethanoic acid water A accepts a proton donates a proton B accepts an electron donates an electron C donates a proton accepts a proton D donates an electron accepts an electron

Question

Aqueous ammonium sulfate is made by reacting aqueous ammonia with dilute sulfuric acid. How is solid ammonium sulfate obtained from the resulting solution? A crystallisation B distillation C filtration D solvent extraction

Question

Carbon forms two oxides: carbon monoxide, CO, and carbon dioxide, CO2. Which row describes these two oxides? CO CO2 A acidic acidic B acidic neutral C neutral acidic D neutral neutral

Question

Group II elements show the same trends as Group I elements. Which statement about elements in Group II is correct? A The melting point of barium is higher than the melting point of calcium. B Barium is more reactive than beryllium. C Strontium would not react with oxygen. D Magnesium is more dense than barium.

Question

Some information about properties of Group I elements is shown. melting point density element / °C in g / cm3 lithium 181 0.53 sodium 98 0.97 potassium X rubidium Y Z What are the values for X, Y and Z? X Y Z A 63 252 0.26 B 63 39 0.26 C 39 63 1.53 D 63 39 1.53

Question

Which statements describe properties of transition elements? 1 They form coloured compounds. 2 They have variable oxidation states. 3 They have low densities. 4 They are volatile. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Which statement about the extraction of aluminium by electrolysis is correct? A Aluminium is extracted from its ore, cryolite. B Aluminium is formed at the positive electrode. C Bauxite is used to lower the temperature of the extraction process. D Graphite is used for both the positive and negative electrodes.

Question

Copper(II) nitrate and zinc carbonate are heated strongly in separate test-tubes. Which row identifies the gases produced? copper(II) nitrate zinc carbonate A oxygen and nitrogen dioxide carbon dioxide only B oxygen and nitrogen dioxide carbon dioxide and oxygen C nitrogen dioxide only carbon dioxide and oxygen D nitrogen dioxide only carbon dioxide only

Question

Iron from a blast furnace can be converted to steel. Which statements about steel are correct? 1 Steel contains more carbon than the iron obtained from the blast furnace. 2 Steel is produced by blowing oxygen through the iron. 3 Calcium oxide is added to molten iron to remove basic oxides. A 1 and 2 B 1 and 3 C 2 and 3 D 2 only

Question

Which metal is used to galvanise steel? A copper B lead C tin D zinc

Question

The diagram shows a stage in the purification of dirty water. dirty water sand pot with holes fine gravel in bottom coarse gravel Which process does this apparatus show? A chlorination B condensation C distillation D filtration

Question

Which substance in polluted air damages stonework and kills trees? A carbon dioxide B carbon monoxide C lead compounds D sulfur dioxide

Question

Which row explains why a high temperature and an iron catalyst are used in the manufacture of ammonia by the Haber process? high temperature iron catalyst A increases the rate of the reaction increases the equilibrium yield of ammonia B increases the rate of the reaction increases the rate of the reaction C increases the equilibrium yield of ammonia increases the equilibrium yield of ammonia D increases the equilibrium yield of ammonia increases the rate of the reaction

Question

The scheme shows four stages in the conversion of sulfur to sulfuric acid. In which stage is a catalyst used? stage A sulfur stage B sulfur sulfur air dioxide air trioxide concentrated stage C sulfuric acid concentrated stage D oleum sulfuric acid water

Question

Which element has an oxide that is used as a food preservative? A helium B hydrogen C iron D sulfur

Question

Which substance gives off carbon dioxide on heating? A lime B limestone C limewater D slaked lime

Question

Which formula represents ethanol? A CH3CH3 B CH2CH2 C CH3CH2OH D CH3COOH

Question

Which statement about structural isomers is correct? A They have the same structure but different reactivity. B They have the same general formula but a different number of carbon atoms in their molecules. C They have the same structure but different relative molecular masses. D They have different structures but the same numbers of each type of atom.

Question

Which formula is the same in methanol, ethanol and propanol? A empirical formula B general formula C molecular formula D structural formula

Question

Ethene reacts with water under suitable conditions. Which statement about this reaction is correct? A The product of this reaction has an Mr of 46. B The reaction produces two different products. C The reaction occurs when ethene gas is bubbled into cold water in the presence of an acid catalyst. D The reaction is a redox reaction.

Question

Ethanoic acid is made by reacting ethanol with acidified potassium manganate(VII). Which type of reaction occurs when ethanol reacts with acidified potassium manganate(VII)? A displacement B fermentation C oxidation D neutralisation

Question

Which structure represents Terylene? H O O O A N C N C N C H H B O O O C C O O C C O O O H H O O D N C N C N C O H

Question

The equation shows the formation of a polymer called Kevlar. n HOOC COOH + n H 2N NH2 – H2 O O O C C N N H H n Which row describes Kevlar? how the polymer is formed type of polymer A addition polymerisation polyamide B addition polymerisation polyester C condensation polymerisation polyamide D condensation polymerisation polyester 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 85 88 89 91 93 96 – 101 103 106 108 112 115 119 122 128 127 131 16 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 89–103 104 105 106 107 108 109 110 111 112 114 116 actinoids Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Cn Fl Lv francium radium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium flerovium livermorium – – – – – – – – – – – – – 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.).