Chemistry 0620/22 February/March 2024: question paper and mark scheme

Question

Solid X is heated for 600 seconds. The graph shows the heating curve that is obtained. 300 200 temperature / °C 100 0 0 100 200 300 400 500 600 time / s What is the melting point of X? A 20 °C B 170 °C C 240 °C D 270 °C

Question

Which statements about diffusion are correct? 1 Aqueous ions cannot diffuse in water. 2 Diffusion is caused by the random movement of particles. 3 Particles spread out in all directions in diffusion. 4 Diffusion can only take place in solids and liquids. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Which statement about an atom of fluorine, , is correct? A It contains a total of 28 protons, neutrons and electrons. B It contains more protons than neutrons. C Its isotopes contain different numbers of protons. D Its nucleus contains 9 neutrons.

Question

Two of the isotopes of calcium are represented as and . Which statement explains why these isotopes of calcium have identical chemical properties? A Both isotopes have the same number of neutrons. B Both isotopes have an electronic configuration of 2,8,8,2. C Both isotopes have a mass number of 20. D Both isotopes have four fully occupied electron shells.

Question

Which statement describes a property of potassium iodide? A It is insoluble in water. B It is a volatile substance. C It has a low melting point. D It conducts electricity when molten.

Question

Methanal, CH2O, has a boiling point of –19 °C. At –20 °C, the liquid methanal is a non-conductor of electricity. In a sample of methanal, each atom of carbon, hydrogen and oxygen has noble gas electronic configuration. Each atom has achieved this electronic configuration in one of three ways: • gaining electrons • losing electrons • sharing electrons. Which statement describes the bonding between the carbon atom and the oxygen atom in methanal? A The carbon atom and the oxygen atom share four electrons. B The carbon atom and the oxygen atom share two electrons. C Carbon is a negative ion and oxygen is a positive ion. These two ions attract each other. D Carbon is a positive ion and oxygen is a negative ion. These two ions attract each other.

Question

The structures of diamond and graphite are shown. Which statement about diamond and graphite is correct? A Diamond and graphite contain strong covalent bonds between carbon atoms. B Diamond and graphite have delocalised electrons. C Diamond and graphite have layered structures. D Diamond and graphite have low melting points.

Question

Which row contains a description of metallic bonding and a property that is explained by reference to metallic bonding? description of property explained by reference metallic bonding to metallic bonding A a lattice of negative ions a metal will react with an in a sea of delocalised electrons acid, producing hydrogen B a lattice of negative ions a piece of a metal can be in a sea of delocalised electrons moulded into different shapes C a lattice of positive ions a metal will react with an in a sea of delocalised electrons acid, producing hydrogen D a lattice of positive ions a piece of a metal can be in a sea of delocalised electrons moulded into different shapes

Question

What is the relative molecular mass, Mr, of sulfur dioxide? A 24 B 32 C 48 D 64 2+ 3+ 2–

Question

Magnetite is an ore of iron which contains the ions Fe , Fe and O only. What is the formula of magnetite? A Fe2O B Fe2O3 C Fe3O2 D Fe3O4

Question

Concentrated aqueous sodium chloride and dilute sulfuric acid are both electrolysed using inert electrodes. Which row identifies the product at the cathode in each electrolysis? aqueous sodium dilute sulfuric acid chloride A hydrogen oxygen B hydrogen hydrogen C chlorine oxygen D chlorine hydrogen

Question

Electrolytes can be broken down by electrolysis. Which rows are correct for each electrolyte? reaction product electrolyte at cathode at anode + – 1 dilute aqueous potassium chloride 2H + 2e → H2 oxygen + – 2 concentrated hydrochloric acid 2H + 2e → H2 chlorine 2– – 3 molten aluminium oxide 2O → O2 + 4e aluminium + – 4 concentrated aqueous sodium bromide Na + e → Na bromine A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Which statement about hydrogen–oxygen fuel cells is correct? A Hydrogen is extracted from clean, dry air. B The only product is carbon dioxide. C The reaction is endothermic. D No toxic gases are produced.

Question

Which statement defines the activation energy, Ea, for a reaction? A It is the minimum energy that colliding particles must have to react. B It is the minimum energy that endothermic reactions take in from their surroundings. C It is the maximum energy that exothermic reactions transfer to their surroundings. D It is the maximum energy released when the bonds in the products of a reaction form.

Question

The equation for the complete combustion of ethyne, H–C≡C–H, is shown. 2H–C≡C–H + 5O=O → 4O=C=O + 2H–O–H The bond energies are listed. bond energy bond in kJ / mol C≡C 837 C–H 415 O=O 498 C=O 805 O–H 464 What is the enthalpy change of the reaction when 1 mol of ethyne is completely burned? A –2472 kJ / mol B –1236 kJ / mol C +1236 kJ / mol D +2472 kJ / mol

Question

In experiment 1, small lumps of limestone are added to dilute ethanoic acid at 40 °C. The volume of carbon dioxide released is measured at regular time intervals. A graph of the results is shown. experiment 1 volume of experiment 2 carbon dioxide released 0 0 time Which changes give the results shown in experiment 2? temperature limestone / °C A large lumps 40 B powder 40 C powder 60 D small lumps 60

Question

In the Haber process, nitrogen and hydrogen are reacted to make ammonia. N2(g) + 3H2(g) ⇌ 2NH3(g) The forward reaction is exothermic. Which conditions produce the maximum yield of ammonia? pressure temperature A high high B high low C low high D low low

Question

The Ostwald process is used to make nitric acid. The conditions used in this process are: 1 a catalyst containing a transition element 2 a pressure of 10 atm 3 a temperature of 800 °C. Which of these conditions are also used in the Contact process? A 1 and 2 B 1 only C 2 and 3 D 3 only

Question

Hydrogen iodide is dissolved in water. + – HI → H + I Which row describes the final colours seen when the solution is tested with damp red litmus paper and with acidified aqueous potassium manganate(VII)? damp red acidified aqueous potassium litmus paper manganate(VII) A blue brown B blue colourless C red brown D red colourless

Question

Which statements about aqueous ethanoic acid are correct? 1 It can be produced by oxidising ethanol with potassium iodide. 2 It reacts with magnesium to produce hydrogen gas. 3 It has an approximate pH value of 3. 4 It produces esters called methanoates. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which element forms an acidic oxide? A calcium B lithium C magnesium D sulfur

Question

Which statement describes the properties of hydrochloric acid? A Carbon dioxide is produced when limestone reacts with hydrochloric acid. B Hydrogen is produced when sodium hydroxide reacts with hydrochloric acid. C Methyl orange turns yellow in strong hydrochloric acid. D Red litmus paper turns blue when dipped into hydrochloric acid.

Question

Elements P and Q have the same number of electron shells. An atom of Q has more electrons in its outer electron shell than an atom of P. Which statements are correct? 1 P and Q are in the same group of the Periodic Table. 2 P and Q are in the same period of the Periodic Table. 3 P has a greater tendency to form positive ions than Q. 4 The oxide of Q is more basic than the oxide of P. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which substance reacts with dilute sulfuric acid to form a salt that can be removed from the resulting mixture by filtration? A aqueous barium chloride B aqueous sodium hydroxide C copper D copper(II) carbonate

Question

Astatine is below iodine in Group VII in the Periodic Table. Which row describes the properties of astatine? state at room reactivity temperature A gas displaces chlorine, bromine and iodine B gas displaces iodine but does not displace chlorine or bromine C solid displaces iodine but does not displace chlorine or bromine D solid does not displace chlorine, bromine or iodine

Question

Which property of copper explains why it is classified as a transition element? A Copper can be bent into different shapes. 2+ + B Copper forms Cu and Cu ions. C Copper is a good conductor of electricity. D Copper has a low density.

Question

Brass is an alloy that is formed from copper and zinc. Which statements are correct? 1 Brass, copper and zinc all conduct electricity. 2 Brass is a compound of copper and zinc. 3 Brass is harder than zinc. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

The equation for the reaction of metal M with aqueous zinc sulfate is shown. M(s) + ZnSO4(aq) → MSO4(aq) + Zn(s) Which statement explains why metal M reacts with aqueous zinc sulfate? A Zinc is less reactive than M because M is able to accept electrons from zinc ions. B Zinc is a more powerful reducing agent than M. C Zinc is more reactive than M because it can lose electrons more easily than M. D Zinc ions can remove electrons from M.

Question

In the blast furnace, the impurity silicon(IV) oxide is removed by the formation of slag. Which equation represents the formation of the substance which reacts with silicon(IV) oxide to form slag? A C + O2 → CO2 B C + CO2 → 2CO C CaCO3 → CaO + CO2 D Fe2O3 + 3CO → 2Fe + 3CO2

Question

Aluminium is extracted from bauxite by electrolysis. Which statement is correct? A Aluminium ions are oxidised to form aluminium. B The cathode has to be replaced regularly because it reacts with the oxygen which is formed. C Carbon dioxide is produced at the anode. D Cryolite is added to remove impurities.

Question

Iron rusts but aluminium does not easily corrode. Which statement explains why aluminium does not easily corrode? A It is an alloy. B It is below iron in the reactivity series. C It is a transition element. D Its surface is protected by an oxide layer.

Question

Which chemicals can be used as a fertiliser to provide the three elements needed for improved plant growth? A (NH2)2CO and KCl B (NH4)2HPO4 and K2SO4 C (NH4)2HPO4 and (NH2)2CO D (NH2)2CO and K2SO4

Question

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

Question

How do carbon dioxide and methane cause global warming? A They emit the thermal energy they have absorbed back to the Earth. B They absorb the radiation directly from the Sun. C They increase thermal energy loss to space. D They reduce reflection of thermal energy from the Earth’s surface.

Question

Four statements about photosynthesis are listed. 1 Chlorophyll is required for photosynthesis. 2 The equation for photosynthesis is C6H12O6 + 6O2 → 6CO2 + 6H2O. 3 Photosynthesis requires energy from light. 4 Photosynthesis releases carbon dioxide, which can lead to climate change. Which statements are correct? A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which molecules are structural isomers? 1 2 H H H H H H H C C C C H H C C C CH3 H CH3 H H H CH3 3 4 H CH3 H H H H H H C C CH3 H C C C C C H CH3 H CH3 H H A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Question

Which statements about the reaction of ethene with steam are correct? 1 The product has a higher molecular mass than ethane. 2 The product reacts with aqueous bromine. 3 The number of electrons shared between carbon atoms decreases. 4 The reaction produces an alcohol and hydrogen. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Question

Methane and chlorine react to form chloromethane. Which row describes the necessary reaction condition and the type of reaction? reaction condition type of reaction A ultraviolet light substitution B nickel catalyst substitution C nickel catalyst addition D ultraviolet light addition

Question

Parts of the structure of two different polymers, X and Y, are shown. X Y O O H H O H O H C C N N C N C N Which row about the monomers and the linkages between the monomers in polymers X and Y is correct? monomers linkages in X and Y A different the linkages in X are different from the linkages in Y B different the linkages in X are the same as the linkages in Y C same the linkages in X are different from the linkages in Y D same the linkages in X are the same as the linkages in Y

Question

Substance Q is tested using paper chromatography. The resulting chromatogram is shown. solvent front baseline Which statement is correct? A Q is a pure substance. B The Rf value of the lower spot is 0.25. C Q is a mixture of at least two different substances. D Q is a compound of two elements. 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 03_0620_22_2024_1.12 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.).