Chemistry 0620/22 October/November 2021: question paper and mark scheme

Question

An experiment is set up as shown. cotton wool soaked cotton wool soaked in ammonia in hydrochloric acid After several minutes, a white ring of ammonium chloride appears as shown. ammonium chloride Which statement explains the observation after several minutes? A Ammonia gas diffuses faster than hydrogen chloride gas because its molecules have a lower molecular mass. B Ammonia gas diffuses faster than hydrogen chloride gas because its molecules have a higher molecular mass. C Ammonia gas diffuses slower than hydrogen chloride gas because its molecules have a lower molecular mass. D Ammonia gas diffuses slower than hydrogen chloride gas because its molecules have a higher molecular mass.

Question

A student put exactly 25.00 cm3 of dilute hydrochloric acid into a conical flask. The student added 2.5 g of solid sodium carbonate and measured the change in temperature of the mixture. Which apparatus does the student need to use? A balance, measuring cylinder, thermometer B balance, pipette, stopwatch C balance, pipette, thermometer D burette, pipette, thermometer

Question

A student separates sugar from pieces of broken glass by dissolving the sugar in water and filtering off the broken glass. filtrate What is the filtrate? A broken glass only B broken glass and sugar solution C pure water D sugar solution

Question

How many protons, neutrons and electrons are there in one atom of the isotope 27 13 Al ? protons neutrons electrons A 13 13 13 B 13 14 13 C 14 13 13 D 14 14 13

Question

Which description of brass is correct? A alloy B compound C element D non-metal

Question

Some properties of diamond are shown. 1 It is very hard. 2 Every atom forms four bonds. 3 It does not conduct electricity. Which properties are also shown by silicon(IV) oxide? A 1 only B 1 and 2 C 1 and 3 D 2 and 3

Question

Which statement describes the attractive forces between molecules? A They are strong covalent bonds which hold molecules together. B They are strong ionic bonds which hold molecules together. C They are weak forces formed between covalently-bonded molecules. D They are weak forces which hold ions together in a lattice.

Question

Which substance is described as a macromolecule? A ammonia B graphite C iron D sodium chloride

Question

The equation for the reaction of sodium with water is shown. 2Na + 2H2O → 2NaOH + H2 What is the volume of hydrogen gas, measured at r.t.p., produced when 18.4 g of sodium reacts with excess water? A 9.6 dm3 B 15.0 dm3 C 19.2 dm3 D 30.0 dm3

Question

Iron can be electroplated with zinc to make it resistant to corrosion. Which row about electroplating iron with zinc is correct? positive electrode negative electrode electrolyte (anode) (cathode) A iron zinc iron nitrate B iron zinc zinc nitrate C zinc iron iron nitrate D zinc iron zinc nitrate

Question

Chlorine reacts with ethane to produce chloroethane and hydrogen chloride. H H H H H C C H + Cl Cl H C C Cl + H Cl H H H H The reaction is exothermic. The bond energies are shown in the table. bond energy bond in kJ / mol C–Cl +340 C–C +350 C–H +410 Cl –Cl +240 H–Cl +430 What is the energy change for the reaction? A –1420 kJ / mol B –120 kJ / mol C +120 kJ / mol D +1420 kJ / mol

Question

Chlorine gas is bubbled into aqueous potassium iodide. What is the ionic equation for the reaction that takes place? A Cl + I– → Cl – + I B Cl 2 + 2I– → Cl 2– + I2 C Cl 2 + 2I– → 2Cl – + I2 D Cl 2 + 2I– → 2Cl – + 2I

Question

Concentrated aqueous sodium chloride is electrolysed. Which equation represents the reaction at the cathode? A Na+ + e– → Na B 2O2– → O2 + 4e– C 2H+ + 2e– → H2 D 2Cl – → Cl 2 + 2e–

Question

Which statements about hydrogen are correct? 1 When hydrogen is burned, heat energy is released. 2 When hydrogen is used in a fuel cell, electrical energy is generated. 3 When hydrogen is used as a fuel, water is the only product. A 1, 2 and 3 B 1 and 2 only C 1 only D 3 only

Question

Solid X is heated strongly. The colour of the solid changes from blue to white. What is solid X? A anhydrous cobalt(II) chloride B calcium carbonate C hydrated copper(II) sulfate D lead(II) bromide

Question

Iron(II) chloride solution reacts with chlorine gas. The equation is shown. 2FeCl 2(aq) + Cl 2(g) → 2FeCl 3(aq) Which statements about this reaction are correct? 1 Fe2+ ions are reduced to Fe3+ ions. 2 Chlorine acts as a reducing agent. 3 Fe2+ ions each lose an electron. 4 Cl 2 molecules are reduced to Cl – ions. A 1 and 2 B 2 and 3 C 2 and 4 D 3 and 4

Question

Which statements about acids and bases are correct? 1 An acid reacts with a metal to give off hydrogen. 2 A base reacts with an ammonium salt to give off ammonia. 3 An acid reacts with a carbonate to give off carbon dioxide. 4 Alkaline solutions are orange in methyl orange. A 1, 2 and 3 B 1, 2 and 4 C 1, 3 and 4 D 2, 3 and 4

Question

Oxide 1 is a solid that reacts with dilute hydrochloric acid. Oxide 2 is a gas that reacts with sodium hydroxide solution. What are the formulae of the oxides? oxide 1 oxide 2 A CaO MgO B MgO NO2 C NO2 SO2 D SO2 CaO

Question

Which reaction is a photochemical reaction? A addition of bromine to propene B esterification of ethanol and ethanoic acid C oxidation of ethanol D substitution of methane with chlorine

Question

The equation shown represents a reaction at equilibrium. m and n represent the balancing numbers for the reactant and product respectively. mP(g) nQ(g) A high temperature increases the concentration of Q. A high pressure increases the concentration of Q. Which statement about the reaction is correct? A The forward reaction is exothermic and m is greater than n. B The forward reaction is exothermic and m is less than n. C The forward reaction is endothermic and m is greater than n. D The forward reaction is endothermic and m is less than n.

Question

A period of the Periodic Table is shown. group I II III IV V VI VII VIII element R S T V W X Y Z The letters are not their chemical symbols. Which statement is correct? A Element R does not conduct electricity. B Elements R and Y react together to form an ionic compound. C Element Z exists as a diatomic molecule. D Element Z reacts with element T.

Question

All metal nitrates are soluble in water. All metal chlorides are soluble except silver and lead. All metal carbonates are insoluble except sodium and potassium. Which aqueous solutions produce a precipitate when mixed together? 1 silver nitrate + sodium carbonate 2 silver nitrate + sodium chloride 3 barium nitrate + potassium chloride A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

Question

Which row describes properties of transition elements? property 1 property 2 property 3 A coloured compounds high density variable oxidation states B high density high melting point one oxidation state C high melting point coloured compounds one oxidation state D low melting point high density variable oxidation states

Question

The noble gases are in Group VIII of the Periodic Table. Which statement explains why noble gases are unreactive? A They all have eight electrons in their outer shells. B They all have full outer shells. C They are all gases. D They are all monoatomic.

Question

Which statement is correct for all metals? A They conduct electricity when molten. B They gain electrons when they form ions. C They have a low density. D They have a low melting point.

Question

Carbon dioxide is produced during the extraction of aluminium from bauxite. Which statement describes how this carbon dioxide is made? A Carbon monoxide reduces aluminium oxide forming carbon dioxide and aluminium. B Carbon is burned in the blast furnace to release heat energy. C Oxygen made in the process reacts with the carbon electrode. D The ore of aluminium undergoes thermal decomposition.

Question

Aluminium objects do not need protection from corrosion. Iron objects must be protected from corrosion. Which statement explains why aluminium resists corrosion? A Aluminium does not form ions easily. B Aluminium does not react with water or air. C Aluminium has a protective oxide layer. D Aluminium is below iron in the reactivity series.

Question

Which statements explain why zinc is used to protect iron from rusting? 1 Zinc is more reactive than iron. 2 Zinc is less reactive than iron. 3 Zinc can form alloys with iron. 4 Zinc acts as a sacrificial metal. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which conditions are used in the Haber process? temperature pressure / °C / atmospheres A 100 10 B 450 10 C 450 200 D 1000 500

Question

Which process does not produce a greenhouse gas? A acid rain on limestone buildings B combustion of wood C digestion in cows D zinc reacting with sulfuric acid

Question

Which reaction involving sulfur dioxide is correct? A It is produced during the extraction of zinc from zinc blende. B It reacts with concentrated sulfuric acid to form oleum. C It reacts with sulfur to form sulfur trioxide. D It turns an acidified solution of potassium manganate(VII) purple.

Question

Lime (calcium oxide) is used to treat waste water from a factory. Which substance is removed by the lime? A ammonia B sodium chloride C sodium hydroxide D sulfuric acid

Question

What is the structure of the ester formed from ethanoic acid and propanol? A B H H O H H O H C C C H H H C C C H H H O C C H H H C H H H H C H O H C D H O H O H C C H C C H H H H H C H O C C C H H H C H H H H H C H O H

Question

Fuel X produces carbon dioxide and water when it is burned in air. So does fuel Y. What could X and Y be? X Y A C H2 B C C8H18 C CH4 H2 D CH4 C8H18

Question

The structures of four organic molecules are shown. H H O H H O H C Cl H C O H H C C O H H C H H H H H How many different homologous series are represented by these molecules? A 1 B 2 C 3 D 4

Question

Which statement about ethene is correct? A It has the chemical formula C2H6. B It burns in excess oxygen producing carbon dioxide and water. C It reacts with Br2 to produce an orange solution. D It reacts with oxygen to form ethanol.

Question

Ethanol is manufactured by fermentation of sugars or by catalytic hydration of ethene. Which row states an advantage of each method? fermentation hydration A produces purer ethanol is a batch process B produces purer ethanol is a continuous process C uses a renewable resource is a batch process D uses a renewable resource is a continuous process

Question

Which statements about unsaturated hydrocarbons are correct? 1 They contain both single and double bonds. 2 They turn aqueous bromine from colourless to brown. 3 They can be manufactured by cracking. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

Question

Which polymers have the same linkage between monomer units? A carbohydrate and polyamide B carbohydrate and polyester C protein and polyamide D protein and polyester

Question

The diagram shows the partial structure of Terylene. O O O C O O C C O From which pair of compounds is it made? O O A HO C C OH + HO OH O O B HO C OH + HO C OH O O C HO OH + HO C C OH O O O O D HO C C OH + HO C C OH 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.).