Chemistry 0620/12 February/March 2024: question paper and mark scheme

Question

Which statement about a solid, a liquid or a gas is correct? A A solid has a fixed shape and can be compressed. B A liquid takes the shape of the container it is in and can be compressed. C A solid has no fixed shape and cannot be compressed. D A gas takes the shape of the container it is in and can be compressed.

Question

Which diagram represents a mixture of compounds? A B C D

Question

Four ions are listed. 3– 3+ + – N Al Li Cl Which pair of ions have the same electronic configuration? 3– + A N and Li 3+ 3– B Al and N – 3+ C Cl and Al + – D Li and Cl

Question

Which statement about isotopes is correct? A Atoms with different numbers of electrons are isotopes of each other. B Atoms with the same mass numbers are isotopes of each other. C Isotopes of the same element have different numbers of neutrons. D Isotopes of the same element have different numbers of protons.

Question

Which statement about the ions formed by the elements in Group VII of the Periodic Table is correct? A All the ions have the same charge of 1–. B All the ions have the same number of electron shells. C Each ion is formed by losing one electron. D Each ion has seven electrons in its outer electron shell.

Question

Which row describes the properties of potassium bromide? soluble melting electrical conductivity in water point when solid A no high good B yes low good C no low poor D yes high poor

Question

Which statement explains why graphite is used as a lubricant? A Each carbon atom in graphite forms three bonds. B The bonding in graphite is covalent. C The carbon atoms are arranged in hexagons. D There are weak forces of attraction between the layers of carbon atoms.

Question

What is the balanced equation for the reaction between magnesium and dilute sulfuric acid? A Mg + H2SO4 → MgSO4 + H2 B Mg + 2H2SO4 → Mg(SO4)2 + 2H2 C 2Mg + H2SO4 → Mg2SO4 + H2 D 2Mg + 3H2SO4 → Mg2(SO4)3 + 3H2

Question

The relative atomic mass, Ar, of an element is the average mass of the isotopes of that element compared to another particle. Which particle is used for this comparison? A a proton 12 B an atom of C 40 C an atom of Ca 1 D an atom of H

Question

The equations for two reactions are shown. equation 1 C + CO2 → x CO equation 2 2C2H6 + 7O2 → 4CO2 + y H2O Which row shows the value of x, the value of y and the equations that are for redox reactions? value of x value of y redox reactions A 1 3 equation 1 only B 2 3 equations 1 and 2 C 2 6 equation 1 only D 2 6 equations 1 and 2

Question

Concentrated aqueous sodium chloride is electrolysed using graphite electrodes. What is the product formed at the cathode? A chlorine B hydrogen C oxygen D sodium

Question

Which row describes the changes that occur when metals burn in oxygen? temperature metal A decreases oxidised B decreases reduced C increases oxidised D increases reduced

Question

When calcium carbonate is heated strongly, carbon dioxide gas is produced. Which words describe the type of change that occurs? A endothermic and chemical B endothermic and physical C exothermic and chemical D exothermic and physical

Question

Which row about a hydrogen–oxygen fuel cell is correct? energy transfer equation for the reaction A chemical to electrical 2H2 + O2 → 2H2O B chemical to electrical 2H2O → 2H2 + O2 C electrical to chemical 2H2 + O2 → 2H2O D electrical to chemical 2H2O → 2H2 + O2

Question

Which list contains only chemical changes? A melting, evaporating, dissolving B rusting, freezing, cracking C neutralisation, polymerisation, combustion D boiling, condensing, distillation

Question

Excess calcium carbonate is added to 50 cm3 of dilute hydrochloric acid of different concentrations in two separate experiments. The volume of gas produced in experiment 1 and in experiment 2 is measured every 30 seconds. The results are shown. concentration of volume of gas volume of gas final volume experiment hydrochloric acid after 30 seconds after 60 seconds of gas 3 3 3 3 in mol / dm in cm in cm in cm 1 0.20 55 99 120 2 0.10 26 50 59 Which diagram represents the data collected? A B 150 150 100 1 100 1 volume of volume of gas / cm3 2 gas / cm3 50 50 2 0 0 0 0 time / s time / s C D 150 150 100 1 100 volume of volume of gas / cm3 gas / cm3 1 50 2 50 2 0 0 0 0 time / s time / s

Question

An experiment is set up as shown. The mass of the conical flask and its contents is measured at 30-second intervals. 50 cm3 dilute hydrochloric acid 1 g calcium carbonate balance Which statement about the reaction and changes to the reaction conditions is correct? 3 3 A Adding 10 cm of water to the 50 cm of acid increases the rate of the reaction. B Increasing the size of the pieces of calcium carbonate increases the rate of the reaction. C Increasing the temperature increases the rate of the reaction. D The mass of the conical flask and its contents increases as carbon dioxide is formed.

Question

Which reaction is reversible? A reaction of aqueous sodium hydroxide with dilute hydrochloric acid B formation of anhydrous copper(II) sulfate from hydrated copper(II) sulfate C oxidation of methane to form carbon dioxide and water D combustion of sulfur to form sulfur dioxide

Question

Silver oxide reacts with magnesium to make silver and magnesium oxide. Ag2O + Mg → 2Ag + MgO Which substance is oxidised in this reaction? A magnesium B magnesium oxide C silver D silver oxide

Question

Compound X dissolves in water to form an aqueous solution. Methyl orange is added to aqueous compound X. The methyl orange turns red. What is compound X? A sodium carbonate B copper(II) oxide C potassium oxide D sulfur dioxide

Question

Dilute hydrochloric acid reacts with aqueous sodium hydroxide in a neutralisation reaction. Which two ions are involved in this neutralisation reaction? + + + – + – – – A Na and H B H and OH C Na and Cl D OH and Cl

Question

The table shows some properties of some of the elements in Group I of the Periodic Table. element melting point / °C reaction with water lithium 181 fizzes steadily sodium 98 fizzes vigorously potassium 64 fizzes very vigorously Rubidium is also an element in Group I of the Periodic Table. Which row describes the properties of rubidium? melting point / °C reaction with water A 39 fizzes slowly B 39 fizzes explosively C 81 fizzes very vigorously D 81 fizzes explosively

Question

Copper(II) sulfate crystals are blue. They are made by adding an excess of copper(II) oxide to sulfuric acid. The mixture is heated and stirred. The mixture is then filtered and the filtrate is allowed to evaporate, leaving blue crystals. Why is filtration necessary? A to remove soluble impurities B to remove sulfuric acid C to remove the blue crystals D to remove unreacted copper(II) oxide

Question

Which barium salts are soluble in water? 1 barium carbonate 2 barium chloride 3 barium nitrate 4 barium sulfate A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Which statement about the properties of elements in Group I or in Group VII is correct? A Bromine displaces iodine from an aqueous solution of potassium iodide. B Chlorine, bromine and iodine are diatomic gases at room temperature. C Lithium, sodium and potassium are soft non-metals. D Lithium, sodium and potassium have an increasing number of electrons in their outer shells.

Question

Rubidium and strontium are both in Period 5 of the Periodic Table. Rubidium is in Group I. Strontium is in Group II. Which statement about these elements is correct? A Each element has five electrons in its outer electron shell. B The atomic number of rubidium is greater than the atomic number of strontium. + 2+ C Rubidium forms the Rb ion; strontium forms the Sr ion. D Electrolysis of molten rubidium chloride and of molten strontium chloride produces hydrogen.

Question

A company needs a metal with a low density which resists corrosion and is a good electrical conductor. Which metal should it use? A aluminium B iron C magnesium D sodium

Question

Which statement about stainless steel is correct? A All atoms in stainless steel are the same size. B Stainless steel is a mixture of copper and zinc. C Stainless steel is an iron compound. D Stainless steel is stronger than pure iron.

Question

Which statements explain why a water tap made of steel is electroplated with copper? 1 It improves the conductivity of the tap. 2 It improves the tap’s resistance to corrosion. 3 It increases the density of the tap. A 1 and 2 B 1 and 3 C 2 only D 3 only

Question

The table shows the results of separately heating four metals with oxides of different metals. The four metals are iron, copper, magnesium and Y. The results are shown. magnesium Y copper iron metal oxide oxide oxide oxide iron ✗ ✗ ✓ ✗ key copper ✗ ✗ ✗ ✗ ✓ = reaction magnesium ✗ ✓ ✓ ✓ ✗ = no reaction Y ✗ ✗ ✓ ✓ What is the order of reactivity of the metals, least reactive first? least reactive most reactive A copper iron Y magnesium B copper Y iron magnesium C magnesium iron Y copper D magnesium Y iron copper

Question

Which metal is most easily obtained from its ore? A aluminium B copper C calcium D iron

Question

Why is distilled water used in chemical experiments rather than tap water? A Distilled water contains fewer chemical impurities. B Distilled water has a better colour. C Distilled water has a higher boiling point. D Distilled water is a better solvent.

Question

Which type of compound is also the name of a homologous series? A carbonate B carboxylic acid C halide D hydroxide

Question

The fractional distillation of petroleum is shown. refinery gas fraction gasoline fraction paraffin fraction diesel oil fraction lubricating oil fraction petroleum bitumen fraction Which fraction is the least volatile? A bitumen B diesel oil C gasoline D refinery gas

Question

Which formula represents an unsaturated hydrocarbon? A C3H6 B C3H8 C C4H10 D C5H12

Question

The structure of an organic compound is shown. H H O C C C C H H H OH The compound is tested separately with thymolphthalein and with aqueous bromine. Which row describes the final colour observed for each test? thymolphthalein aqueous bromine A blue colourless B blue orange C colourless colourless D colourless orange

Question

Which statement describes methane? A It is an alcohol. B It is an unsaturated molecule. C It contains carbon, hydrogen and oxygen atoms only. D Its molecules contain four single covalent bonds.

Question

Which row explains why plastics such as poly(ethene) cause pollution? produce toxic accumulate in the gases when burned oceans A no no B no yes C yes no D yes yes

Question

Two experiments are described. experiment 1 A large mass of copper(II) sulfate is stirred into a beaker of water. After a few minutes, undissolved crystals are visible on the bottom of the beaker. experiment 2 Sea water is distilled. Distilled water and solid impure salt are separated into two containers. Which statement is correct? A In experiment 1, the undissolved crystals are the filtrate. B In experiment 1, the water is the solute. C In experiment 2, sea water boils at 100 °C. D In experiment 2, the impure salt is a residue.

Question

An aqueous sample of X is heated with aqueous sodium hydroxide and small pieces of aluminium. A gas is produced which turns damp red litmus paper blue. Aqueous sodium hydroxide is added to a second aqueous sample of X. A pale green precipitate is observed. What is X? A ammonium nitrate B chromium(II) chloride C iron(II) nitrate D iron(II) sulfate 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 – – – 03_0620_12_2024_1.23b 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.).