Chemistry 0620/13 May/June 2025: question paper and mark scheme

Question

Liquid iron is cooled to form solid iron. Which statement about the particles in iron is correct? A The particles move further apart. B The particles move faster. C The position of the particles becomes fixed. D The attractions between the particles become weaker.

Question

Which diagram shows a mixture of an element and a compound? A B C D

Question

Which statement about elements and their atoms is correct? A Aluminium is in the second period of the Periodic Table and has two occupied electron shells. B Helium is in Group VIII of the Periodic Table and has eight outer shell electrons. C Lithium is in Group I of the Periodic Table and has one occupied electron shell. D Sulfur is in the third period of the Periodic Table and has six outer shell electrons.

Question

An atom of the element erbium is represented by 167 68 Er. Which row shows the number of protons, neutrons and electrons in this atom? protons neutrons electrons A 68 99 68 B 68 99 99 C 99 68 68 D 99 68 99

Question

Rubidium is in Group I of the Periodic Table and bromine is in Group VII of the Periodic Table. Rubidium reacts with bromine to form an ionic compound. Which row shows the electron change taking place for rubidium and the correct formula of the rubidium ion formed? electron change formula of ion formed A electron gained Rb+ B electron gained Rb– C electron lost Rb+ D electron lost Rb–

Question

Which dot-and-cross diagram represents the electronic configuration for the outer shell electrons in ammonia, NH3? A B H N H H N H H H C D H N H H N H H H

Question

Which statements about graphite are correct? 1 Each carbon atom is covalently bonded to four other carbon atoms. 2 Graphite is an electrical conductor because it contains ions that are free to move. 3 Graphite is used as a lubricant because it has layers that slide over each other. A 1 and 2 B 1 only C 2 and 3 D 3 only

Question

Which equation represents the reaction of magnesium with dilute hydrochloric acid? A Mg(s) + 2HCl (aq) → MgCl 2(aq) + H2(g) B Mg(s) + 2HCl (l) → MgCl 2(s) + H2(g) C 2Mg(s) + 2HCl (aq) → 2MgCl (aq) + H2(g) D 2Mg(s) + 2HCl (l) → 2MgCl (s) + H2(g)

Question

The relative formula mass, Mr, of calcium carbonate, CaCO3, is 100. What is the mass of carbon present in 100 g of calcium carbonate? A 12 g B 36 g C 40 g D 60 g

Question

What is the definition of relative atomic mass? 1 A It is the average mass of the isotopes of an element compared to th of the mass of an 12 atom of 12C. 1 B It is the total mass of the isotopes of an element compared to th of the mass of an 12 atom of 12C. 1 C It is the average mass of an element compared to th of the mass of an atom of 12C. 12 1 D It is the total mass of an element compared to th of the mass of an atom of 12C. 12

Question

Which row describes the electrolysis of molten potassium bromide? product at anode product at cathode A bromine hydrogen B bromine potassium C hydrogen bromine D potassium bromine

Question

What is produced in a hydrogen–oxygen fuel cell? A hydrogen and oxygen B hydrogen only C carbon dioxide D water

Question

When ammonium nitrate is added to water, the temperature of the mixture decreases. The ammonium nitrate can be recovered by evaporating the water. Which statement explains these observations? A The ammonium nitrate dissolves in the water, and the process is endothermic. B The ammonium nitrate reacts with the water, and the process is endothermic. C The ammonium nitrate dissolves in the water, and the process is exothermic. D The ammonium nitrate reacts with the water, and the process is exothermic.

Question

Magnesium is reacted with dilute hydrochloric acid. The table shows the total volume of hydrogen produced every 15 seconds. time / s 0 15 30 45 60 75 90 105 120 total volume of 0 18 32 48 59 64 68 72 74 hydrogen / cm3 During which time period is the rate of reaction the fastest? A 0–30 seconds B 30–60 seconds C 60–90 seconds D 90–120 seconds

Question

Which substance forms a blue solution when it is added to water? A cobalt(II) chloride B copper(II) sulfate C thymolphthalein D universal indicator

Question

Steam reacts with carbon to produce carbon monoxide and hydrogen. C(s) + H2O(g) → CO(g) + H2(g) Which substance is reduced in the reaction? A C B CO C H2 D H2O

Question

Three compounds are listed. 1 aluminium nitrate 2 ammonium chloride 3 ammonium nitrate All three compounds are heated with aqueous sodium hydroxide. Which compounds produce ammonia? A 1 and 3 B 1 only C 2 and 3 D 2 only

Question

A solution containing hydroxide ions, OH–(aq), is added to a solution containing hydrogen ions, H+(aq). An equation representing the reaction is shown. H+(aq) + OH–(aq) → H2O(l) Which statement about the reaction is correct? A The hydrogen ions represent an alkali. B The reaction is a neutralisation reaction. C The reaction is a reduction. D As the OH– ions are added, the pH of the reaction mixture falls.

Question

Which compound is an acidic oxide? A barium oxide B carbon dioxide C copper(II) oxide D magnesium oxide

Question

Which statement describes a hydrated salt? A It is an aqueous solution of a salt. B It is a solid salt that is chemically combined with water. C It is a solid salt that contains no water. D It is a salt that has been broken down by water.

Question

In the Periodic Table, how does the metallic character of the elements vary from left to right across a period? A It decreases. B It increases. C It increases then decreases. D It stays the same.

Question

Lithium, sodium and potassium are elements in Group I of the Periodic Table. Which statements about these elements are correct? 1 They react with water to produce hydrogen. 2 The melting point increases down the group. 3 The density decreases down the group. 4 The reactivity increases down the group. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

X, Y and Z are each one of the elements chlorine, bromine and iodine. When aqueous X is mixed with aqueous ions of Y, there is no reaction. When aqueous Y is mixed with aqueous ions of Z, there is no reaction. Which statement is correct? A X is more reactive than Y. B X is a pale yellow-green gas at room temperature and pressure. C Y is a red-brown liquid at room temperature and pressure. D Z is less reactive than Y.

Question

Which row describes the properties of a transition element? melting point density colour and state / °C at r.t.p. of its oxide at r.t.p. A –210 low brown gas B 113 high white solid C 650 low white solid D 1085 high red solid

Question

Which statements about the elements in Group VIII are correct? 1 They all have eight electrons in their outer electron shell. 2 They all react with sodium to form ionic compounds. 3 They are all monatomic gases. A 1 and 2 B 1 only C 2 and 3 D 3 only

Question

Sulfur and potassium are two elements in the Periodic Table. Which row identifies the element with the higher thermal conductivity and the element with the lower malleability? higher thermal lower conductivity malleability A sulfur potassium B sulfur sulfur C potassium sulfur D potassium potassium

Question

Three statements about aluminium and copper are listed. 1 The density of aluminium is less than that of copper. 2 The electrical conductivity of copper is higher than that of aluminium. 3 Aluminium is more reactive than copper. Which statements explain why aluminium is used instead of copper to make overhead power cables? A 1 and 2 B 1 and 3 C 1 only D 2 and 3

Question

The table gives some information about the reactions of four metals, J, K, L and M. metal reactions J reacts with steam and hydrochloric acid but not with cold water K reacts with hydrochloric acid but not with steam or cold water L reacts with hydrochloric acid and with cold water M does not react with hydrochloric acid What is the order of reactivity of metals J, K, L and M? most least reactive reactive A L J K M B L K J M C M J K L D M K J L

Question

What is the chemical name for rust? A anhydrous iron(II) oxide B anhydrous iron(III) oxide C hydrated iron(II) oxide D hydrated iron(III) oxide

Question

Water from natural sources can contain many dissolved substances. Which substances are often harmful to aquatic life? 1 dissolved oxygen 2 nitrates 3 phosphates A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Which gas is over 30% of clean, dry air? A argon B carbon dioxide C nitrogen D oxygen

Question

Farmers use fertilisers to replace elements in the soil that have been removed by the crops they grow. Which elements in the soil are replaced by adding fertilisers? A Ca, P, O B K, O, S C N, O, S D N, K, P

Question

The equation for the reaction between carbon dioxide and water in the presence of chlorophyll and sunlight is shown. chlorophyll carbon dioxide + water glucose + oxygen sunlight Which process does this equation represent? A combustion B decomposition C displacement D photosynthesis

Question

Which statement about members of a homologous series is correct? A They are elements with the same chemical properties. B They are compounds with the same functional group. C They are atoms with the same number of outer shell electrons. D They are molecules with the same boiling point.

Question

The molecular formulae of four organic compounds, W, X, Y and Z, are shown. W X Y Z C3H8O C3H6 C4H8O2 C6H14 Which statement about compounds W, X, Y and Z is correct? A W and Z could both be alcohols. B Y is the only compound that could be a carboxylic acid. C W is a hydrocarbon. D X is ethene.

Question

Fractional distillation is used to separate petroleum into useful fractions. Which statement about the properties of the fractions of petroleum is correct? A The refinery gas fraction has a lower volatility than the gasoline fraction. B The molecules in the gasoline fraction have a longer chain length than the molecules in the naphtha fraction. C The naphtha fraction has a higher boiling point than the kerosene fraction. D The fuel oil fraction has a higher viscosity than the diesel oil fraction.

Question

Which statements about the alkanes are correct? 1 They are generally unreactive except in terms of combustion and substitution by chlorine. 2 They have the general formula CnH2n+2. 3 They contain double carbon–carbon covalent bonds. 4 They decolourise aqueous bromine. A 1, 2 and 3 B 1 and 2 only C 1, 3 and 4 D 2 and 4

Question

Which products can be formed by the cracking of one molecule of hexane, C6H14? A C4H10 and C2H4 only B C12H26 and H2 only C C3H7 only D C2H6 and C4H10 only

Question

Three coloured inks, P, Q and R, are tested using paper chromatography. The chromatogram is shown. P Q R Which statement is correct? A P is a pure substance. B P and Q have a colour that could be the same in both inks. C The top line of the chromatogram is called the baseline. D All the colours in R are also in Q.

Question

The table shows the results of two separate tests on a sample of aqueous T. test observation flame test yellow flame add dilute nitric acid effervescence What is the identity of T? A sodium chloride B calcium chloride C sodium carbonate D calcium carbonate 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.).