Chemistry 0620/22 May/June 2025: question paper and mark scheme

Question

An ice cube melts. ice cube pool of water What happens to the molecules of water in the ice cube? A They evaporate. B They dissolve. C They gain energy. D They lose energy.

Question

A sample of a liquid, X, is heated to a temperature above its boiling point. X is then cooled, so that it condenses and then freezes. Which graph describes the change in temperature of X over time? A B temperature / °C temperature / °C time / s time / s C D temperature / °C temperature / °C time / s time / s

Question

Which row gives the number of protons, electrons and neutrons in an atom of zinc? protons electrons neutrons A 30 30 35 B 30 35 35 C 35 30 30 D 35 35 30

Question

Which particles have the electronic configuration 2,8,8? 1 an argon atom, Ar 2 an aluminium ion, Al 3+ 3 a sodium ion, Na+ 4 a chloride ion, Cl – A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

A sample of element Q has two isotopes. Their relative masses and abundances are shown. relative mass abundance of isotope /% 238 66 244 34 What is the relative atomic mass of this sample of Q to three significant figures? A 240 B 241 C 242 D 243

Question

Which statement about silicon(IV) oxide, SiO2, is correct? A It conducts electricity because it contains delocalised electrons. B It has a giant covalent structure with each silicon atom bonded to four oxygen atoms. C It is a simple covalent molecule. D Its structure is similar to that of graphite.

Question

When 65 g of zinc reacts with 32 g of sulfur, 97 g of zinc sulfide is produced. When 65 g of zinc reacts with 40 g of sulfur, the mass of zinc sulfide produced is still 97 g. Which statement explains this observation? A Some of the zinc sulfide evaporates. B The reaction rate is slow. C The reaction stops before it is complete. D Zinc is the limiting reactant.

Question

Aluminium reacts with iron(III) oxide to form aluminium oxide and iron. Which chemical equation for the reaction between aluminium and iron(III) oxide is correct? A Al + FeO → Al O + Fe B 2Al + Fe2O → Al 2O + 2Fe C Al + Fe2O3 → Al 2O3 + Fe D 2Al + Fe2O3 → Al 2O3 + 2Fe

Question

The concentration of a solution of aqueous sodium hydroxide is 0.50 mol / dm3. Which mass of sodium hydroxide is used to make 500 cm3 of this solution? A 10 g B 20 g C 40 g D 160 g

Question

Molten zinc oxide is electrolysed using inert electrodes. Which row identifies the product at each electrode? anode cathode A zinc oxygen B hydrogen oxygen C oxygen zinc D oxygen hydrogen

Question

Dilute aqueous sodium chloride is electrolysed using platinum electrodes. What is the half-equation for the reaction at the cathode? A 2H+ + 2e– → H2 B Na+ + e– → Na C 2Cl – → Cl 2 + 2e– D 4OH– → 2H2O + O2 + 4e–

Question

Hydrogen–oxygen fuel cells can be used to power vehicles. Which statement about hydrogen–oxygen fuel cells is correct? A The equation for the overall reaction is H2 + O2 → H2O2. B The only chemical products are water and carbon dioxide. C Chemical energy in the fuel is converted into electrical energy. D The hydrogen used in hydrogen–oxygen fuel cells is a fossil fuel.

Question

A reaction pathway diagram is shown. products energy reactants progress of reaction Which row identifies the type of reaction and how the temperature of the surroundings changes during the reaction? temperature of type of reaction the surroundings A endothermic decreases B endothermic increases C exothermic decreases D exothermic increases

Question

The average bond energy for the C–H bond is 413 kJ / mol. What is the enthalpy change when 1.0 mol of methane molecules is formed from carbon and hydrogen atoms? A –1652 kJ B – 413 kJ C +413 kJ D +1652 kJ

Question

Which statement describes the effect of adding a catalyst to a chemical reaction? A The activation energy, Ea, of the reaction is increased. B The enthalpy change, ΔH, of the reaction stays unchanged. C The frequency of collisions between the particles is decreased. D The kinetic energy of the particles is increased.

Question

Which row describes the conditions used in the manufacture of sulfuric acid by the Contact process? catalyst pressure temperature A iron high high B iron low low C vanadium(V) oxide high low D vanadium(V) oxide low high

Question

Which equations show the underlined species acting as a reducing agent? 1 Fe2O3 + 3CO → 2Fe + 3CO2 2 Fe + CuSO4 → FeSO4 + Cu 3 5Fe2+ + MnO4– + 8H+ → 5Fe3+ + Mn2+ + 4H2O 4 Fe(OH)2 + H2SO4 → FeSO4 + 2H2O A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

A farmer incorrectly adds two substances to the soil at the same time. They react together to form a gas which turns damp red litmus paper blue. What are the two substances? A a basic oxide and a potassium salt B a basic oxide and an ammonium salt C an acidic oxide and a potassium salt D an acidic oxide and an ammonium salt

Question

Which row shows the equations for the dissociation of hydrochloric acid and of ethanoic acid in aqueous solution? hydrochloric acid ethanoic acid A HCl (aq) o H+(aq) + Cl –(aq) CH3COOH(aq) H+(aq) + CH3COO–(aq) B HCl (aq) H+(aq) + Cl –(aq) CH3COOH(aq) H+(aq) + CH3COO–(aq) C HCl (aq) o H+(aq) + Cl –(aq) CH3COOH(aq) o H+(aq) + CH3COO–(aq) D HCl (aq) H+(aq) + Cl –(aq) CH3COOH(aq) o H+(aq) + CH3COO–(aq)

Question

Which three oxides are all acidic? A CaO, NO2, SO2 B CaO, CO2, Na2O C CO2, NO2, SO2 D CO2, Na2O, SO2

Question

The table shows some properties of noble gases. density boiling point noble gas in g / dm3 in °C helium 0.2 –269 neon 0.9 –246 argon 1.8 –186 krypton xenon 5.9 –108 Which row predicts the density and the boiling point of krypton? density boiling point in g / dm3 in °C A 1.4 –75 B 2.4 –195 C 3.8 –153 D 8.5 –213

Question

Sodium is a Group I metal. What is a physical property of sodium? A non-conductor of electricity B high melting point C high density D malleable

Question

Tennessine (atomic number 117) is a manufactured element that is below astatine in Group VII of the Periodic Table. What is the expected state of tennessine at room temperature and pressure? A a diatomic gas B a liquid C a monatomic gas D a solid

Question

When chlorine is bubbled into aqueous sodium bromide, a displacement reaction occurs. Which description of this reaction is correct? A Chloride displaces bromide. B Chlorine displaces bromine. C Chloride displaces bromine. D Chlorine displaces bromide.

Question

Brass is an alloy of copper. Which statement about brass or copper is correct? A Brass does not conduct electricity because it is a compound. B Copper conducts electricity because its atoms are free to move. C Brass is harder than copper because its layers of atoms cannot easily slide over each other. D Copper is stronger than brass because it is a pure metal.

Question

The ionic equations for some reactions between metals and aqueous metal ions are shown. Cu + 2Ag+ → 2Ag + Cu2+ Mg + Zn2+ → Mg2+ + Zn Zn + Cu2+ → Cu + Zn2+ Sn + Cu2+ → Sn2+ + Cu Which further information can be used to place copper, magnesium, silver, tin and zinc in order of their reactivity? A Zinc reacts with Sn2+ ions. B Copper does not react with Sn2+ ions. C Magnesium reacts with Cu2+ ions. D Magnesium reacts with Ag+ ions.

Question

Zinc is used to galvanise iron to prevent it from rusting. Which statements are correct? 1 Galvanising is an example of a barrier method. 2 If the zinc is scratched, the iron will rust very quickly. 3 Galvanising is an example of sacrificial protection. 4 Zinc is more reactive than iron and so accepts electrons more readily. A 1, 2 and 4 B 1 and 3 C 2, 3 and 4 D 2 and 3 only

Question

Which equation represents a reaction that occurs in a blast furnace during the extraction of iron from hematite? A Ca + CO2 → CaO + CO B Fe2O3 + 3Ca → 2Fe + 3CaO C Ca(OH)2 → CaO + H2O D Fe2O3 + 3CO → 2Fe + 3CO2

Question

Water is added separately to anhydrous copper(II) sulfate and to anhydrous cobalt(II) chloride. Which row shows the colour changes? anhydrous anhydrous copper(II) sulfate cobalt(II) chloride A blue to white blue to pink B blue to white pink to blue C white to blue blue to pink D white to blue pink to blue

Question

Gases which cause acid rain form in car engines. These gases can be removed using a catalytic converter. Which equation represents the removal of one of these gases using a catalytic converter? A CO2 + C → 2CO B 2CO + 2NO → 2CO2 + N2 C N2 + 2O2 → 2NO2 D 2NO + O2 → 2NO2

Question

Which statements about carbon dioxide are correct? 1 Carbon dioxide absorbs thermal energy from the Earth. 2 Carbon dioxide increases the thermal energy loss to space. 3 The level of carbon dioxide in the atmosphere has increased due to the burning of fossil fuels. 4 Carbon dioxide is the only gas that causes global warming. A 1 and 2 B 1 and 3 C 2 and 3 D 2 and 4

Question

What is the structural formula of butan-2-ol? A CH3CH2CH2OH B CH3CH(OH)CH3 C CH3CH2CH2CH2OH D CH3CH2CH(OH)CH3

Question

Methanol reacts with ethanoic acid to form an ester. What is the displayed formula for this ester? A B O H O H H H C O C H H C O C C H H H H C D H O H H O H H H C C O C H H C C O C C H H H H H H

Question

Petroleum can be separated into useful fractions by fractional distillation. Which row shows a correct use of the named fraction? fraction use A bitumen lubricant B naphtha fuel for home heating C kerosene jet fuel D refinery gas making chemicals

Question

Ethane reacts with chlorine in the presence of ultraviolet light. Which products are formed? A Cl CH2CH2Cl and H2 B 2CH3Cl and H2 C C2H5Cl and HCl D CH2=CH2 and 2HCl

Question

Ethanol can be made by the fermentation of aqueous glucose and by the catalytic addition of steam to ethene. What are two advantages of making ethanol by the catalytic addition of steam to ethene rather than by the fermentation of aqueous glucose? A faster reaction and renewable raw materials B purer product and faster reaction C renewable raw materials and continuous process D uses more energy and forms a purer product

Question

The structure of a polymer repeat unit is shown. H H H O H H N C C N C C C C H H H H H O n Which pair of monomers is used to make this polymer? monomer 1 monomer 2 H H H H H O O H A N C C N C C H H H H O O H H H H H O H H O H B N C C N C C C C H H H H O H H O H H H H H H H O O H C N C C C C N C C H H H H H H O O H H H H H H H O H H O H D N C C C C N C C C C H H H H H H O H H O

Question

Which item of apparatus is used to measure exactly 26.3 cm3 of a liquid? A B C D

Question

A mixture containing an aqueous salt and an insoluble salt is filtered. X Y Which row describes X and Y? X Y A solute pure water B solute filtrate C residue pure water D residue filtrate

Question

Pure ethanol has a melting point of –114 °C and a boiling point of 78 °C. What are the melting and boiling points of a sample of ethanol with glucose dissolved in it? melting boiling point / °C point / °C A –116 77 B –116 79 C –112 77 D –112 79 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.).