Chemistry 0620/22 October/November 2023: question paper and mark scheme

Question

Part of a cooling curve for water is shown. 100 temperature / qC X Y 0 time / min What is occurring between points X and Y? A Steam is condensing into water. B The temperature of the water is decreasing. C Ice is melting. D Particles are losing heat to the surroundings.

Question

Which statements about clean, dry air are correct? 1 It is a mixture of elements only. 2 It is a mixture of elements and compounds. 3 It contains only non-metals. A 1 and 3 B 1 only C 2 and 3 D 2 only

Question

A representation of an atom is shown. – + + – – + + + – – + – What is the nucleon number of this atom? A 6 B 7 C 12 D 13

Question

The percentage abundances of three isotopes in a sample of neon are shown. percentage isotope abundance / % 20 10 Ne 90.48 21 10 Ne 0.27 22 10 Ne 9.25 What is the relative atomic mass, Ar, of this sample of neon? A 10.19 B 20.19 C 21.00 D 30.19

Question

Potassium reacts with iodine to form potassium iodide. Which statement about potassium iodide is correct? A Each potassium atom shares a pair of electrons with an iodine atom. B In potassium iodide, the particles of potassium have more protons than electrons. C Potassium iodide has a high melting point because it is a covalent compound. D Potassium iodide has a low melting point because it is an ionic compound.

Question

Which substance has the lowest melting point? A graphite B methanol C silicon(IV) oxide D sodium chloride

Question

The diagram shows the structure of a molecule of ethyl ethanoate. H O H C C H H H O C C H H H What is the molecular formula of a molecule of ethyl ethanoate? A CHO B C4H8O2 C C4(H2)2(O2) D C2H4O

Question

A hydrocarbon contains 85.7% of carbon by mass. What is the empirical formula of the hydrocarbon? A CH2 B CH4 C C2H5 D C3H6

Question

The formula of a compound containing element X is Na2X2O3. The relative formula mass of the compound is 158. What is the relative atomic mass of X? A 32 B 59.5 C 64 D 119

Question

Dilute aqueous potassium chloride is electrolysed using platinum electrodes. Which row identifies the product at each electrode? anode cathode A chlorine hydrogen B chlorine potassium C oxygen hydrogen D oxygen potassium

Question

Concentrated aqueous copper(II) chloride is electrolysed using copper electrodes, as shown. power supply + – copper electrodes aqueous copper(II) chloride What happens to the mass of each electrode during this process? positive electrode negative electrode A decreases decreases B decreases increases C increases decreases D increases increases

Question

The initial and final temperatures of four different reactions are measured. Which reaction is the least exothermic? initial final temperature temperature / °C / °C A 19 25 B 21 18 C 22 17 D 22 26

Question

Which equation represents an endothermic reaction? A Cl 2(g) → 2Cl (g) B CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) C H(g) + H(g) → H2(g) D 2K(s) + 2H2O(l) → 2KOH(aq) + H2(g)

Question

Methane burns in oxygen to form carbon dioxide and water. CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) The bond energies are shown. bond energy bond in kJ / mol C–H 410 C–O 360 C=O 805 O–H 460 O–O 146 O=O 496 What is the energy change for this reaction? A –818 kJ / mol B –102 kJ / mol C +102 kJ / mol D +818 kJ / mol

Question

Hydrochloric acid is added to excess calcium carbonate in two separate experiments. Two different concentrations of hydrochloric acid are used but the temperature is the same in both experiments. The graph of the results shows the volume of carbon dioxide gas given off over time. 2.0 mol / dm3 volume of carbon dioxide given off 1.0 mol / dm3 time Which row is correct? particles in 2.0 mol / dm3 compared to 1.0 mol / dm3 collision rate collision energy A higher no change B higher higher C lower no change D lower higher

Question

The decomposition of dinitrogen tetroxide, N2O4, into nitrogen dioxide, NO2, is a reversible reaction. The equation for the reaction is shown. N2O4(g) 2NO2(g) The forward reaction is endothermic. Which row shows the effect on the position of equilibrium and the rate of the reverse reaction when the temperature is increased? position of rate of the equilibrium reverse reaction A shifts to the left decreases B shifts to the left increases C shifts to the right decreases D shifts to the right increases

Question

In a blast furnace, iron(III) oxide is converted to iron and carbon monoxide is converted to carbon dioxide. Fe2O3 + 3CO → 2Fe + 3CO2 What happens to each of these reactants? A Both iron(III) oxide and carbon monoxide are oxidised. B Both iron(III) oxide and carbon monoxide are reduced. C Iron(III) oxide is oxidised and carbon monoxide is reduced. D Iron(III) oxide is reduced and carbon monoxide is oxidised.

Question

Which row describes what happens to Fe2+ ions when they are oxidised? oxidation number electron movement of iron A they gain electrons decreases B they gain electrons increases C they lose electrons decreases D they lose electrons increases

Question

In which reaction does an acid react with a base? A Dilute sulfuric acid is added to a piece of magnesium ribbon producing hydrogen. B Dilute sulfuric acid is added to aqueous barium chloride producing a white precipitate of barium sulfate. C Aqueous sodium hydroxide is added to aqueous copper(II) sulfate producing a blue precipitate of copper(II) hydroxide. D Aqueous sodium hydroxide is added to solid ammonium sulfate producing gaseous ammonia.

Question

Which element forms an oxide that reacts with an aqueous solution of a base? A argon B sulfur C magnesium D copper

Question

Which method is used to produce insoluble salts? A addition of excess insoluble base to an acid B addition of excess metal to an acid C precipitation using two aqueous solutions D titration using an acid and an alkali

Question

The noble gases are in Group VIII of the Periodic Table. Some properties of the first four noble gases are shown. boiling point density noble gas in °C in g / dm3 helium –267 0.179 neon –246 0.900 argon –186 1.782 krypton –152 3.708 Which row identifies the trends in boiling point and in density as Group VIII is descended? boiling point density A decreasing increasing B increasing increasing C decreasing decreasing D increasing decreasing

Question

Some properties of element R are shown. melting point in °C 98 boiling point in °C 883 reaction with cold water gives off H2 gas reaction when heated with oxygen burns to give a white solid In which part of the Periodic Table is R found? A Group I B Group VII C Group VIII D transition elements

Question

Which pair of compounds shows that transition elements have variable oxidation states? A Cr2O3 and CrBr3 B CuSO4 and CuCl 2 C Fe2O3 and FeCl 2 D NiO and NiCl 2

Question

The list gives the order of some metals and hydrogen in the reactivity series. Metal X is also included. most reactive K Mg Zn H X least reactive Cu Which row shows the properties of metal X? reacts with oxide reduced dilute acids by carbon A no no B no yes C yes no D yes yes

Question

When zinc is added to an aqueous solution containing magnesium ions, there is no reaction. Which species has the greatest tendency to lose electrons? A Mg B Mg2+ C Zn D Zn2+

Question

Which gas in the air is needed for iron to rust? A argon B carbon dioxide C nitrogen D oxygen

Question

Which coating prevents iron from rusting even when the coating is damaged? A grease B paint C plastic D zinc

Question

Why is limestone added to the blast furnace? A It neutralises the molten slag produced. B It reacts with impurities to form slag. C It releases carbon dioxide which reduces the iron(III) oxide. D It removes acidic gases such as carbon dioxide.

Question

The flow chart shows stages in the treatment of river water to produce drinking water. river sedimentation stage stage drinking water tank J K water What occurs at stages J and K? J K A distillation chlorination B distillation filtration C filtration chlorination D filtration distillation

Question

Carbon dioxide acts as a greenhouse gas by interacting with a particular type of energy that radiates from the Earth’s surface into the atmosphere. Which type of energy is involved and what happens when this energy interacts with carbon dioxide molecules? type of what happens energy involved A thermal carbon dioxide molecules increase the Earth’s energy loss to space B thermal carbon dioxide molecules absorb the energy C light carbon dioxide molecules increase the Earth’s energy loss to space D light carbon dioxide molecules absorb the energy

Question

Oxides of nitrogen, such as NO and NO2, are formed in the petrol engines of cars. They are removed from the exhaust gases by reactions in the car’s catalytic converter. Which row describes how oxides of nitrogen are formed in a petrol engine and a reaction that happens in the catalytic converter? a reaction that happens how oxides of nitrogen are formed in the catalytic converter A by the reaction between 2NO + 2CO → N2 + 2CO2 nitrogen and oxygen from the air B by the reaction between 2NO + 2H2 → N2 + 2H2O nitrogen and oxygen from the air C by the reaction between nitrogen 2NO + 2CO → N2 + 2CO2 compounds in petrol and oxygen from the air D by the reaction between nitrogen 2NO + 2H2 → N2 + 2H2O compounds in petrol and oxygen from the air

Question

Which diagram shows the displayed formula for the named organic compound? A B C D H O H H H O H H H H C C O O H H C C H H C C H H C C H H H H H H H H ethanoic acid ethene ethanol methane

Question

What is the total number of covalent bonds in a molecule of butane, C4H10? A 3 B 10 C 13 D 14

Question

Propane reacts with chlorine in a substitution reaction. Which reaction condition is required for the reaction to occur? A acid catalyst B iron catalyst C temperature of 400 °C D ultraviolet light

Question

The structure of an organic compound is shown. H H H H C C C O H H H H Which structure represents a molecule that reacts with steam to produce this product? A B C D H H H H H H H H H H C C H C C C H H C C O H H C C C H H H H H H H H H

Question

Which term describes nylon? A addition polymer B natural polymer C polyamide D polyester

Question

Ethene can be polymerised. Which diagram represents the structure of the product formed? A B C D H H H H H H H H H H C C C C C C H C C C C H H H H H n H H n H H H H

Question

An acid–base titration is described. ● 25.0 cm3 of dilute aqueous alkali is put into a conical flask. ● Indicator is added to the flask. ● Dilute acid is added to the aqueous alkali until the indicator changes colour. ● The volume of acid used is then recorded. Which use of apparatus is correct? A The 25.0 cm3 of aqueous alkali is measured using a volumetric pipette. B The 25.0 cm3 of aqueous alkali is measured using the lines on the conical flask. C The volume of acid is measured using a measuring cylinder. D The volume of acid is measured using a volumetric pipette.

Question

Substance Q is investigated using chromatography. The chromatogram is shown. The diagram is not drawn to scale. solvent front Q 129 mm 114 mm 83 mm baseline 13 mm Q What is the Rf value of Q? A 0.60 B 0.64 C 0.69 D 0.72 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.).