Chemistry 0620/12 February/March 2025: question paper and mark scheme

Question

Substance L takes the shape of the container that holds it. What could be the state of matter of substance L? A liquid or gas B gas or solid C solid or liquid D solid only

Question

The melting points and boiling points of pure substances M, N and O are shown. M N O melting point / °C –114 115 –101 boiling point / °C 78 445 –34 The substances are chlorine, ethanol and sulfur. Which row identifies M, N and O? M N O A chlorine ethanol sulfur B ethanol sulfur chlorine C sulfur chlorine ethanol D sulfur ethanol chlorine

Question

Which statement explains why the noble gases are unreactive? A They are in the same group of the Periodic Table. B They are gases at room temperature. C They each have a full outer electron shell. D They are found in air.

Question

What is the electronic configuration of a P3– ion? A 2,8,2 B 2,8,5 C 2,8,6 D 2,8,8

Question

Some information about four metal atoms or ions is shown. atom proton number of nucleon charge or ion number electrons number Q +3 10 27 R +2 12 24 S +2 10 26 T 16 16 Which two atoms or ions are from isotopes of the same element? A Q and R B Q and T C R and S D S and T

Question

Which row describes the changes to the atoms when a metal and a non-metal react together? metal atoms non-metal atoms A gain electrons to form anions lose electrons to form cations B gain electrons to form cations lose electrons to form anions C lose electrons to form anions gain electrons to form cations D lose electrons to form cations gain electrons to form anions

Question

In the following diagrams, X and Y are atoms of different elements. Which diagram correctly shows the arrangement of outer shell electrons in a molecule of methane? A B C D Y Y Y X Y X Y Y X Y Y X Y Y Y Y Y

Question

Which pathway describes the properties of graphite? Is it covalently bonded? yes no Does it conduct Does it conduct electricity when solid? electricity when solid? yes no yes no A B C D

Question

Which row identifies the formula of the named substance? substance formula A cobalt(II) chloride CuCl 2 B ethane C2H6 C helium He2 D iron(III) oxide Fe3O2

Question

Antifreeze contains a mixture of water and ethylene glycol. The diagram shows their displayed formulae. H H O H C O H H O O C H H H H H H H H H C O H O C H O H C O H H H O C H H H H What is the molecular formula of ethylene glycol? A CHO B C2H6O2 C C2H8O3 D C6H18O6

Question

The equation for the reaction of magnesium with oxygen is shown. 2Mg + O2 → 2MgO In an experiment, 6.0 g of magnesium is reacted with excess oxygen. Which mass of magnesium oxide, MgO, is produced? A 10 g B 20 g C 40 g D 80 g

Question

Which products are formed when dilute sulfuric acid undergoes electrolysis? product formed product formed at the anode at the cathode A oxygen hydrogen B hydrogen oxygen C sulfur dioxide hydrogen D oxygen sulfur dioxide

Question

The diagram shows an experiment to electroplate a nickel spoon with silver. power supply nickel spoon electrolyte Which row correctly describes the positive electrode, the negative electrode and the electrolyte? positive negative electrolyte electrode electrode A nickel spoon pure nickel silver nitrate solution B nickel spoon pure silver nickel nitrate solution C pure nickel nickel spoon silver nitrate solution D pure silver nickel spoon silver nitrate solution

Question

When dilute sulfuric acid reacts with aqueous sodium hydroxide, the temperature of the solution increases. Which words describe this reaction? A endothermic and neutralisation B endothermic and redox C exothermic and neutralisation D exothermic and redox

Question

Which statement is correct for both physical and chemical changes? A Covalent bonds are broken and formed during the changes. B The total mass of substance is the same before and after the changes. C The changes are usually reversible. D The temperature always rises or falls during the changes.

Question

A sample of calcium carbonate reacts with dilute hydrochloric acid to produce a final volume of 60 cm3 of gas. The reaction finishes after 120 seconds. The experiment is repeated at a lower temperature. All other conditions stay the same. Which row shows the results of the second experiment? final volume of gas time for reaction produced / cm3 to finish / s A 40 120 B 40 160 C 60 120 D 60 160

Question

In which equation is the iron oxidised? A C + FeO → CO + Fe B 3CO + Fe2O3 → 3CO2 + 2Fe C Fe2O3 + H2 → 2FeO + H2O D PbO + Fe → Pb + FeO

Question

HOCl is an acid. NH4OH is an alkali. Which row shows the ions present in aqueous solutions that identify the acid and the alkali? HOCl (aq) NH4OH(aq) A H+ H+ B H+ OH– C OH– H+ D OH– OH–

Question

Which elements form an oxide that reacts with water to produce a blue solution with thymolphthalein? 1 calcium 2 carbon 3 sulfur A 1 and 2 B 1 only C 2 and 3 D 3 only

Question

A sample of fertiliser is tested by warming it with aqueous sodium hydroxide. A colourless gas is produced which turns damp red litmus paper blue. Which element, essential for plant growth, must be present? A nitrogen B phosphorus C potassium D sulfur

Question

Insoluble solid magnesium carbonate reacts with dilute sulfuric acid. The equation is shown. magnesium carbonate + sulfuric acid → magnesium sulfate + water + carbon dioxide The steps used to make crystals of magnesium sulfate are listed. step 1 Add excess magnesium carbonate to dilute sulfuric acid and stir the mixture. step 2 Filter the mixture. step 3 Heat the filtrate to the point of crystallisation. step 4 Leave the filtrate to cool. What is the residue removed from the mixture in step 2? A magnesium carbonate B sulfuric acid C magnesium sulfate D water

Question

Which trend occurs across the period from sodium to argon? A a change from metal to non-metal B an increase in melting point C a more violent reaction with water D an increase in electrical conductivity

Question

Which statement about the element bromine is correct? A It displaces chlorine from aqueous potassium chloride. B It has a higher density than chlorine. C It is a diatomic metal. D It is a green gas at room temperature.

Question

Metallic element X has a high density. Which part of the Periodic Table is X in? A Group I B halogens C transition elements D Group VIII

Question

Which statement about the uses of metals is correct? A Aluminium has a low density and good electrical conductivity which make it suitable for overhead electrical cables. B Aluminium food containers can only be used for a short time because chemicals in the food react with the aluminium. C Electrical wiring made from copper is covered with plastic because copper corrodes easily. D Copper is used in the manufacture of aircraft because it has a low density and is not malleable.

Question

Steel bridges are painted to help stop rust from forming on their surfaces. What causes steel to rust? A water, oxygen and sunlight B water and oxygen only C water and sunlight only D oxygen and sunlight only

Question

Which two metals are mixed together to make brass? 1 tin 2 zinc 3 nickel 4 copper A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Metal M is between zinc and iron in the reactivity series. Which statements about metal M are correct? 1 It reacts with cold water to produce hydrogen gas. 2 It does not react with cold water but will react with dilute hydrochloric acid. 3 The metal can be obtained from its oxide by heating it strongly with carbon. 4 The metal oxide cannot be reduced using carbon. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

What is the colour change when water is added to anhydrous copper(II) sulfate? A blue to white B blue to pink C pink to blue D white to blue

Question

Which statement about the composition of clean, dry air is correct? A It contains 78% oxygen. B It contains 21% nitrogen. C It contains less than 1% argon. D It contains 4% carbon dioxide.

Question

Which row identifies a source and an adverse effect of methane? source adverse effect A car engines acid rain B car engines climate change C decomposition of vegetation acid rain D decomposition of vegetation climate change

Question

Which statements about alkenes are correct? 1 Propene is a saturated hydrocarbon. 2 Ethene is made by heating long-chain alkanes to a high temperature in the presence of a catalyst. 3 Hexene reacts with aqueous bromine, changing its colour from colourless to orange. 4 Ethene, propene and butene have the same general formula. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

The table shows the formulae and names of some organic compounds. formula name 1 CH3Cl chloroethane 2 CH3COOH ethanoic acid 3 BrCH2CH2Br 1,2-dibromoethane 4 (CH3COO)2Ca calcium methanoate Which rows give the correct name for the formula shown? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Which gas is the main constituent of natural gas? A hydrogen B nitrogen C methane D oxygen

Question

A sample of petroleum is separated into three fractions, X, Y and Z, using fractional distillation. Some properties of X, Y and Z are listed. ● X is more viscous than Z. ● Y has a higher boiling point than X. Which fraction has the longest carbon chain and which fraction is the most volatile? longest most volatile carbon chain A Y X B Y Z C Z X D Z Y

Question

Two salt solutions, P and Q, are tested. The table shows the results. test P Q a few drops of aqueous green precipitate red-brown sodium hydroxide are added forms precipitate forms a few drops of dilute nitric acid and no change seen white precipitate a few drops of barium nitrate are added forms a few drops of dilute nitric acid and white precipitate no change seen a few drops of silver nitrate are added forms What are P and Q? P Q A iron(II) chloride iron(III) sulfate B iron(III) chloride iron(III) sulfate C iron(II) sulfate iron(III) chloride D iron(III) sulfate iron(III) chloride

Question

A small quantity of a solid, E, is added to a large excess of aqueous ethanoic acid. No bubbles of gas are seen and the solid dissolves to give a colourless solution. What is solid E? A calcium hydroxide B copper(II) oxide C magnesium D sodium carbonate

Question

Ethanol is manufactured by two different processes. Which raw materials are used by the two processes to make ethanol? 1 glucose 2 ethane 3 ethene 4 steam A 1, 2 and 4 B 1, 3 and 4 C 1 and 3 only D 2 and 4 only

Question

What is used to test for chlorine? A a glowing splint B damp litmus paper C limewater D aqueous potassium manganate(VII)

Question

Which statement about paper chromatography is correct? A It can show if a substance is pure. B It can separate a mixture of insoluble substances. C It can separate a compound into its elements. D It provides a way of combining substances to make new coloured compounds. 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.).