Chemistry 0620/22 February/March 2019: question paper and mark scheme

Question

Pure water boils at 100 °C. What happens to the water particles when water boils? A They gain energy and move further apart. B They gain energy and stay close together. C They lose energy and move further apart. D They lose energy and stay close together.

Question

Which method should be used to separate a mixture of two liquids? A crystallisation B electrolysis C filtration D fractional distillation

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Lead(II) iodide is insoluble in water. Lead(II) iodide is made by adding aqueous lead(II) nitrate to aqueous potassium iodide. Which pieces of apparatus are needed to obtain solid lead(II) iodide from 20 cm3 of aqueous lead(II) nitrate? 1 2 3 4 5 A 1, 2 and 4 B 1, 3 and 5 C 1, 4 and 5 D 2, 4 and 5

Question

The chromatogram of substance S is shown. Some distances, W, X, Y and Z, are labelled on the diagram. solvent front substance S W X Y Z baseline solvent level How is the Rf value of substance S calculated? A X B W C Y D Y Y Z X W

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Which row describes isotopes of the same element? number of protons number of neutrons A different different B different same C same different D same same

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Which row describes the structure of the positive ion in sodium chloride? protons electrons neutrons A 11 11 12 B 11 10 12 C 17 17 18 D 17 18 18

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Which statement about copper, diamond and silicon(IV) oxide is correct? A Copper and silicon(IV) oxide have similar electrical conductivity. B In diamond the carbon atoms are covalently bonded as flat sheets. C In silicon(IV) oxide the silicon and oxygen atoms are covalently bonded as flat sheets. D The structure of copper includes a lattice of positive ions.

Question

An oxide of nitrogen has the following composition by mass: N, 30.4%; O, 69.6%. It has a relative molecular mass of 92. What is the molecular formula of the oxide of nitrogen? A NO B NO2 C NO4 D N2O4

Question

Calcium carbonate reacts with dilute hydrochloric acid according to the equation shown. CaCO3 + 2HCl → CaCl 2 + CO2 + H2O 10 g of calcium carbonate is reacted with 100 cm3 of 1 mol / dm3 hydrochloric acid. The following statements are made. 1 1.2 dm3 of carbon dioxide is formed. 2 5.6 g of calcium chloride is formed. 3 4.8 g of carbon dioxide is formed. 4 No calcium carbonate is left when the reaction is completed. Which statements about the reaction are correct? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Which substance is not produced during the electrolysis of concentrated aqueous sodium chloride? A chlorine B hydrogen C sodium D sodium hydroxide

Question

Aqueous copper(II) sulfate is electrolysed using copper electrodes. What are the ionic half-equations for the reactions that occur at each electrode? anode cathode A Cu → Cu2+ + 2e– Cu2+ + 2e– → Cu B Cu2+ + 2e– → Cu Cu → Cu2+ + 2e– C 4OH– → 2H2O + O2 + 4e– Cu2+ + 2e– → Cu D 4OH– → 2H2O + O2 + 4e– 2H+ + 2e– → H2 12 10 g of ammonium nitrate is added to water at 25 °C and the mixture stirred. The ammonium nitrate dissolves and, after one minute, the temperature of the solution is 10 °C. Which word describes this change? A endothermic B exothermic C neutralisation D reduction

Question

In the question paper above.

Question

Hydrogen reacts with chlorine according to the following equation. H2(g) + Cl 2(g) → 2HCl (g) The reaction is exothermic. Which statement about this reaction is correct? A Energy absorbed for bond breaking is greater than the energy released in bond making. B Energy absorbed for bond breaking is less than the energy released in bond making. C Energy released in bond breaking is greater than the energy absorbed in bond making. D Energy released in bond breaking is less than the energy absorbed in bond making.

Question

Hydrogen-oxygen fuel cells can be used to power cars. Platinum is used as a catalyst. The amount of energy produced per gram is shown for three fuels. energy produced fuel per g of fuel / kJ hydrogen 143 methane 55 petrol 44 Which statement is correct and is an advantage of a hydrogen-oxygen fuel cell? A Hydrogen is difficult to store. B Hydrogen produces less energy per gram than methane or petrol. C Platinum is rare and expensive. D The only product is water.

Question

A student adds dilute hydrochloric acid at two different temperatures to two different lumps of limestone. The lumps of limestone have the same mass. The carbon dioxide gas produced is collected in a gas syringe. The volume of carbon dioxide collected in 1 minute at each temperature is shown. volume of carbon dioxide temperature / °C produced in 1 minute / cm3 25 10 50 40 Which row describes and explains the results obtained at 50 °C compared with 25 °C? reaction rate energy of collisions A higher lower B higher higher C lower lower D lower higher

Question

Which reaction is reversible? A Cu + ZnSO4 → CuSO4 + Zn B CuO + H2SO4 → CuSO4 + H2O C CuO + H2 → Cu + H2O D CuSO4•5H2O → CuSO4 + 5H2O

Question

Some nitrogen dioxide gas was put in a gas syringe. The end of the gas syringe is sealed. A reversible reaction occurs. The reaction reaches equilibrium. 2NO2(g) N2O4(g) dark brown light yellow The forward reaction is exothermic. Which statement about the reaction is correct? A If the gas syringe is placed in a cold water bath, the colour becomes darker. B If the gas syringe is placed in a hot water bath, the colour becomes lighter. C If the volume in the gas syringe is increased, the colour becomes lighter. D If the volume in the gas syringe is decreased, the colour becomes lighter.

Question

The reaction between magnesium and carbon dioxide is shown in the equation. 2Mg + CO2 → 2MgO + C Which statement describes what happens in this reaction? A Carbon is oxidised. B Magnesium is reduced. C Neither oxidation nor reduction happens. D The carbon in carbon dioxide is reduced.

Question

Which changes involve reduction? 1 2I– → I2 + 2e– 2 CuO + H2 → Cu + H2O 3 Al 3+ + 3e– → Al 4 Pb2+ + SO42– → PbSO4 A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Barium hydroxide is an alkali. It reacts with hydrochloric acid. How does the pH of the hydrochloric acid change as an excess of aqueous barium hydroxide is added? A The pH decreases from pH 14 and becomes constant at pH 7. B The pH decreases from pH 14 to about pH 1. C The pH increases from pH 1 and becomes constant at pH 7. D The pH increases from pH 1 to about pH 14.

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Which statement describes a chemical property of aluminium oxide, Al 2O3? A It reacts with acids but not with bases. B It reacts with acids and bases. C It reacts with bases but not with acids. D It reacts with water.

Question

The results of two tests on an aqueous solution of X are shown. test observation aqueous sodium hydroxide added green precipitate formed acidified aqueous silver nitrate added yellow precipitate formed What is X? A copper(II) chloride B copper(II) iodide C iron(II) chloride D iron(II) iodide

Question

Four stages used to prepare an insoluble salt are listed. 1 drying 2 filtration 3 precipitation 4 washing In which order are the stages done? A 2→1→3→4 B 3→2→4→1 C 3→4→1→2 D 4→3→2→1

Question

The elements sodium to argon form Period 3 of the Periodic Table. Which row describes the trend across Period 3 from left to right? number of outer metallic group number shell electrons character A decreases decreases decreases B decreases increases decreases C increases decreases increases D increases increases increases

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 statement explains why elements in Group VIII of the Periodic Table are unreactive? A They are monatomic gases. B They form stable diatomic molecules. C They have a full outer shell of electrons. D They share electrons with each other.

Question

In which reaction does Fe(s) form ions when the mixture is heated? A Fe(s) + CaO(s) B Fe(s) + MgO(s) C Fe(s) + ZnO(s) D Fe(s) + CuO(s)

Question

The list gives the order of some metals and hydrogen in the reactivity series. Metal X is also included. most reactive K Mg Zn H X least reactive Cu Which row correctly shows the properties of metal X? reacts with oxide reduced dilute acids by carbon A no no B no yes C yes no D yes yes

Question

Which metal carbonate does not produce carbon dioxide when it is heated? A copper(II) carbonate B iron(II) carbonate C potassium carbonate D zinc carbonate

Question

Which statement about the extraction of metals is correct? A Aluminium is extracted by the electrolysis of hematite. B Cryolite acts as a reducing agent in the extraction of aluminium. C Zinc is extracted by the electrolysis of zinc blende. D Zinc is obtained by heating zinc oxide with coke.

Question

The diagram shows how water is treated to make it suitable for drinking. stage 1 stage 2 stage 3 stage 4 reservoir drinking chlorination of water water What happens in stage 2? A condensation B sublimation C evaporation D filtration

Question

What are the main substances produced by the fractional distillation of liquid air? A oxygen and carbon dioxide B oxygen and nitrogen C helium and nitrogen D hydrogen and oxygen

Question

The raw materials for the Haber process are hydrogen and nitrogen. What are the sources of the hydrogen and nitrogen? A hydrogen from ethanol and nitrogen from NPK fertilisers B hydrogen from methane and nitrogen from air C hydrogen from sulfuric acid and nitrogen from air D hydrogen from water and nitrogen from ammonium nitrate

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Which process removes carbon dioxide from the Earth’s atmosphere? A combustion B heating limestone C photosynthesis D respiration

Question

The Contact process is used to make sulfuric acid. The steps in the process are listed. 1 Dissolve sulfur trioxide in 98% concentrated sulfuric acid. 2 Heat sulfur strongly in air. 3 Add oleum to water. 4 Pass sulfur dioxide over a vanadium(V) oxide catalyst. Which sequence of steps is correct? A 4→1→2→3 B 4→2→3→1 C 2→1→4→3 D 2→4→1→3

Question

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

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Which statement about members of a homologous series is correct? A Successive members differ by CH3. B Successive members have a molecular mass that differs by 14. C They have the same molecular formula. D They have identical physical properties.

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Ethanol is manufactured on a large scale by fermentation. Which statement about fermentation is correct? A It is a continuous process. B A renewable raw material is used. C It is a very fast reaction. D The ethanol produced is pure.

Question

The structure of a compound, G, is shown. G is in the same homologous series as ethanoic acid. H H O H C C C O H H H Which row describes some of the properties of an aqueous solution of G? produces a gas turns methyl orange with magnesium yellow A no yes B no no C yes no D yes yes

Question

Which statement about polymers is correct? O A Nylon contains the C N linkage. H B Nylon is a polyester. C Propane can be polymerised by addition polymerisation. D The linkage in Terylene contains a carbon-carbon double bond. 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 85 88 89 91 93 96 – 101 103 106 108 112 115 119 122 128 127 131 16 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 89–103 104 105 106 107 108 109 110 111 112 114 116 actinoids Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Cn Fl Lv francium radium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium flerovium livermorium – – – – – – – – – – – – – 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.).