Chemistry 0620/23 May/June 2024: question paper and mark scheme

Question

Sodium chloride is a liquid at 900 °C. Which row describes the arrangement and the motion of the particles in sodium chloride at 900 °C? arrangement motion of particles of particles A regular vibrate about a fixed point B regular move randomly C random vibrate about a fixed point D random move randomly

Question

Hydrogen chloride gas, HCl, reacts with ammonia gas, NH3, to form solid ammonium chloride. The apparatus is set up as shown. After a few minutes, a white cloud of solid ammonium chloride forms where the two gases meet. solid ammonium chloride source of source of hydrogen chloride gas ammonia gas The experiment is repeated using hydrogen bromide gas, HBr, in place of hydrogen chloride. How far along the tube does the white cloud of solid ammonium bromide form? A B C D source of source of hydrogen bromide gas ammonia gas

Question

Substances P and Q both conduct electricity. P is a mixture of two different types of atom. Q is made of only one type of atom. Which row describes P and Q? P Q A alloy element B alloy compound C compound alloy D compound element

Question

An atom of element R contains 15 protons, 16 neutrons and 15 electrons. What is R? A gallium B phosphorus C sulfur D zinc

Question

Which molecule contains a double covalent bond between two atoms of the same element? A carbon dioxide B ethanol C ethene D nitrogen

Question

Silicon(IV) oxide is a covalently bonded compound. Which statements are correct? 1 Silicon atoms form four single bonds in silicon(IV) oxide. 2 Oxygen atoms form two double bonds in silicon(IV) oxide. 3 Silicon(IV) oxide has a high melting point. 4 Silicon(IV) oxide contains one silicon atom and four oxygen atoms. A 1 and 2 B 1 and 3 C 2 and 3 D 3 and 4

Question

The equation for the reaction of iron(III) oxide with carbon monoxide is shown. Fe2O3 + 3CO → 2Fe + 3CO2 What is the percentage yield of iron when 16.8 g of carbon monoxide reacts completely with iron(III) oxide to form 8.96 g of iron? A 26.7% B 40.0% C 53.3% D 80.0%

Question

What is the volume of 14.5 g of gaseous butane, C4H10 , at room temperature and pressure? 3 3 3 96.0 cm 6.0 cm 96.0 dm 3 A B C D 6.0 dm

Question

Aqueous copper(II) sulfate is electrolysed using copper electrodes. d.c. power supply copper + – copper aqueous copper(II) sulfate Which statement describes what happens during the electrolysis? A Copper atoms gain electrons at the cathode and copper(II) ions lose electrons at the anode. B Electrons move in the external circuit from the positive electrode to the negative electrode. C Copper(II) ions move through the electrolyte from the cathode to the anode. D Copper is formed at the cathode and oxygen is formed at the anode.

Question

Electrolysis is carried out on concentrated aqueous potassium bromide using inert electrodes. Which products are formed at the anode and the cathode? anode cathode A bromine hydrogen B bromine potassium C hydrogen bromine D hydrogen potassium

Question

Hydrogen–oxygen fuel cells and gasoline are each used to power cars. Which statement describes an advantage of using hydrogen–oxygen fuel cells in cars in comparison with gasoline engines? A Hydrogen is a non-renewable resource. B Hydrogen is produced during the fractional distillation of petroleum. C Hydrogen–oxygen fuel cells do not release carbon dioxide. D Hydrogen–oxygen fuel cells need electricity to work.

Question

Plant cells use energy from sunlight for photosynthesis. Which row describes and explains the energy change that occurs? type of explanation of energy change energy change A endothermic less energy is released making bonds than is absorbed to break bonds B endothermic more energy is released making bonds than is absorbed to break bonds C exothermic less energy is released making bonds than is absorbed to break bonds D exothermic more energy is released making bonds than is absorbed to break bonds

Question

Two different experiments are done to find the enthalpy change, ΔH, of each reaction. The temperature of each reaction mixture is measured at the beginning of the reaction and after 3 minutes. experiment 1 experiment 2 30 20 30 40 25 15 25 35 20 10 20 30 initial temperature temperature initial temperature temperature / °C after 3 minutes / °C after 3 minutes / °C / °C Which row gives the correct sign for the value of ΔH for each experiment and identifies if the reaction is endothermic or exothermic? experiment 1 experiment 2 A negative and endothermic positive and exothermic B negative and exothermic positive and endothermic C positive and endothermic negative and exothermic D positive and exothermic negative and endothermic

Question

The reaction pathway diagram for an endothermic reaction is shown. u, v and w are known energy values. w products v energy reactants u progress of reaction Which diagram shows the reaction pathway diagram when a catalyst is used in the reaction? A B w w v v energy products energy reactants reactants u u products progress of reaction progress of reaction C D w w products products v v energy energy reactants reactants u u progress of reaction progress of reaction

Question

Which process is a physical change? A burning a piece of magnesium B reacting calcium carbonate with hydrochloric acid C melting an ice cube D the rusting of an iron nail

Question

The Contact process is used to convert sulfur dioxide to sulfur trioxide. Vanadium(V) oxide is the catalyst in this process. 2SO2(g) + O2(g) ⇌ 2SO3(g) The forward reaction in this equilibrium is exothermic. Which statements about this process are correct? 1 The catalyst increases the rate of both the forward and backward reactions. 2 A low pressure increases the yield of sulfur trioxide. 3 A low pressure is used to keep the costs low. 4 A high temperature increases the yield of sulfur trioxide. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Question

The equation for the decomposition of hydrogen peroxide, H2O2, is shown. 2H2O2 → 2H2O + O2 3 In an experiment, the total volume of oxygen produced is 100 cm . The experiment is repeated using 1.00 g of a solid catalyst. All other conditions remain the same. Which row describes the total volume of oxygen and the mass of the catalyst at the end of the second experiment? total volume of oxygen mass of catalyst 3 / cm /g A more than 100 less than 1.00 B 100 less than 1.00 C 100 1.00 D more than 100 1.00

Question

Nitrogen reacts with hydrogen to form ammonia in the presence of an iron catalyst. The reaction is reversible. N2(g) + 3H2(g) ⇌ 2NH3(g) Which statement about this reaction is correct? A The iron catalyst decreases the activation energy of only the forward reaction. B When equilibrium is reached, the forward reaction has stopped. C When the pressure changes, the concentration of ammonia at equilibrium remains constant. D Nitrogen and hydrogen never completely convert to ammonia.

Question

The equation for a redox reaction is shown. H2O2 + 2KI + H2SO4 → I2 + K2SO4 + 2H2O Potassium iodide is …… 1 …… agent in this reaction because iodide ions …… 2 …… electrons. Which words complete gaps 1 and 2? 1 2 A an oxidising lose B an oxidising gain C a reducing lose D a reducing gain

Question

Element E is in Group II of the Periodic Table. Which row describes element E and its oxide? element E oxide of E A metal acidic B metal basic C non-metal acidic D non-metal basic

Question

Lead(II) iodide is formed as a precipitate in the reaction shown. Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2NaNO3(aq) Which method is used to separate the lead(II) iodide from the mixture? A crystallisation B distillation C evaporation D filtration

Question

Which statement explains why sulfur, S, has similar chemical properties to selenium, Se? A They both have the same number of electrons in their outer electron shell. B They are both solids at room temperature and pressure. C They are both non-metals. D They both form negative ions.

Question

Atoms of sodium, rubidium and element Q each have one outer shell electron. Some properties of these elements are shown. melting point boiling point density element 3 in °C in °C in g / cm sodium 98 883 0.97 rubidium 39 688 1.53 Q 28 672 1.87 What is Q? A hydrogen B lithium C potassium D caesium

Question

Which statement about elements in Group VIII of the Periodic Table is correct? A They all have a full outer shell of electrons. B They all react with Group I elements to form ionic compounds. C They are all diatomic molecules. D They are all liquids at room temperature and pressure.

Question

The electrical conductivity of magnesium is tested. Magnesium is then added to dilute sulfuric acid. A gas, W, is produced. Which row describes the electrical conductivity of magnesium and identifies W? electrical conductivity gas W of magnesium A good hydrogen B good oxygen C poor hydrogen D poor oxygen

Question

Aluminium metal is extracted from its purified ore by electrolysis. Which statement about the electrolyte in this process is correct? A The electrolyte is purified molten bauxite only. B The electrolyte is purified bauxite dissolved in molten cryolite. C The electrolyte is purified molten cryolite only. D The electrolyte is purified cryolite dissolved in molten bauxite.

Question

Part of the reactivity series is shown. potassium X calcium Y aluminium Which metals are represented by X and Y? X Y A copper magnesium B sodium magnesium C sodium silver D copper silver

Question

Some substances found in water extracted from a river are listed. 1 plastics 2 nitrates 3 oxygen Which substances are harmful to aquatic life? A 1 and 2 B 1 and 3 C 2 only D 3 only

Question

Car engines which use gasoline as a fuel produce oxides of nitrogen. Oxides of nitrogen are removed from the exhaust gases. Which statements about the formation or removal of oxides of nitrogen are correct? 1 Gasoline reacts with nitrogen in the air to produce oxides of nitrogen. 2 Gasoline contains nitrogen. 3 Nitrogen and oxygen react at high temperatures to produce oxides of nitrogen. 4 Nitrogen monoxide, NO, reacts with carbon monoxide, CO, in a catalytic converter. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Question

Which structures represent a pair of structural isomers? 1 CH3CH2CH2CH2CH2CH3 2 CH3CH2CH2CH2CH(CH3)2 3 CH3CH(CH3)CH2CH2CH3 4 CH3CH(CH3)CH2CH2CH2CH3 A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Question

Alkanes are a homologous series of hydrocarbons. The table shows the names and boiling points of the first four members of this series. name boiling point / °C methane –162 ethane – 89 propane – 42 butane 0 Pentane is the next member of the series. Which row gives the molecular formula and the boiling point of pentane? molecular formula boiling point / °C A C5H10 36 B C5H12 –51 C C5H10 –51 D C5H12 36

Question

Which displayed formula represents the ester formed by the reaction of propan-1-ol with ethanoic acid? A B H O H H O H C C H H H H C C C H H H H O C C C H H H O C C C H H H H H H H C D H H O H O H C C C H H H C C H H H H O C C H H O C C H H H H H

Question

Ethanol can be manufactured by fermentation and by the catalytic addition of steam to ethene. Which statement identifies an advantage of using one of these methods? A Catalytic addition requires a high temperature and pressure. B Ethanol produced by fermentation is extracted by distillation. C Fermentation is a batch process. D The raw material in fermentation is a renewable resource.

Question

Which statement about carboxylic acids is correct? A They react with alkalis to form a salt and water. B They react with metals to form a salt and water. C They react with metal carbonates to form a salt, water and hydrogen. D The general formula for carboxylic acids is CnH2n+1OH.

Question

The structure of a polymer is shown. H O H O N C N C Which statement about this polymer is correct? A Alkenes are polymerised to make the polymer. B It is a polyester. C It is an addition polymer. D Water is produced when the polymer is made.

Question

Methane undergoes substitution reactions with chlorine and complete combustion with excess oxygen. Which row about the two reactions is correct? condition for equation for the complete combustion reaction with chlorine A an acid catalyst methane + oxygen → carbon dioxide + hydrogen B an acid catalyst methane + oxygen → carbon dioxide + water C ultraviolet light methane + oxygen → carbon dioxide + hydrogen D ultraviolet light methane + oxygen → carbon dioxide + water

Question

What is used to identify the end-point of an acid–base titration? A balance B measuring cylinder C indicator D volumetric pipette

Question

Four pure substances, P, Q, R and S, are tested using chromatography. The same solvent is used each time. The table shows the distance moved by each substance and by the solvent from the baseline. distance moved by distance moved by substance substance solvent / cm / cm P 4.5 10.0 Q 3.0 20.0 R 4.5 20.0 S 13.5 30.0 Which two substances are identical? A P and R B P and S C Q and R D Q and S

Question

A substance is tested with three different reagents. Which row shows the results obtained with aqueous iron(II) nitrate? aqueous acidified aqueous acidified aqueous sodium hydroxide silver nitrate barium nitrate A green precipitate, no reaction no reaction insoluble in excess B green precipitate, white precipitate white precipitate insoluble in excess C white precipitate, cream precipitate no reaction insoluble in excess D white precipitate that no reaction white precipitate dissolves in excess

Question

A student carries out a flame test on a sample. The flame colour observed is light green. Which ion is present in the sample? 2+ 2+ + + A Ba B Ca C Li D K 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 20 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 06_0620_23_2024_1.16e 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.).