Chemistry 0620/22 October/November 2020: question paper and mark scheme

Question

Which gas has the slowest rate of diffusion? A H2 B NH3 C CH4 D CO2

Question

A chromatography experiment is carried out to analyse the pigments present in four different types of leaf. The student carrying out the experiment forgot to complete his table of results, which is shown. distance number of colour of distance travelled plant travelled by pigments identified from the origin by Rf value leaf the solvent identified pigments each pigment (cm) front (cm) green green: 3.0 green: 0.81 maple F 3.7 / yellow yellow: 3.1 yellow: 0.83 green green: 2.5 green: 0.78 laurel 2 G / yellow yellow: 2.5 yellow: 0.78 green green: 2.9 green: 0.83 lime 3 / yellow 3.5 yellow: 3.0 yellow: 0.86 / orange orange: 2.7 yellow: 0.77 green green: 2.8 green: 0.80 ash 3 / yellow 3.5 yellow: 3.0 yellow: H / orange orange: 2.7 orange: 0.77 Which row identifies the values of F, G and H? F G H A 2 3.2 0.80 B 3 3.5 0.83 C 2 3.2 0.86 D 3 3.5 0.78

Question

Which statement about isotopes is correct? A They have different proton numbers. B They have different chemical properties. C They have the same nucleon number. D They have the same number of electrons in their outer shell.

Question

In the chromatography experiment shown, which label represents the solvent front? A B D C

Question

Different methods of separation rely on substances having different properties. Which property does distillation make use of? A boiling point B colour C particle size D solubility in different solvents

Question

The arrangements of the electrons in two ions formed from elements X and Y are shown. X Y n = 20 n = 20 p = 19 p = 17 Which equation represents the reaction between elements X and Y? A X2 + 2Y → 2X+ + 2Y– B X2 + 2Y → 2X– + 2Y+ C 2X + Y2 → 2X+ + 2Y– D 2X + Y2 → 2X– + 2Y+

Question

Which row identifies compounds that contain single covalent bonds only, double covalent bonds only or both single and double covalent bonds? single covalent bonds double covalent bonds both single and only only double covalent bonds A C2H4 CH3OH CO2 B CH3OH C2H4 CO2 C CH3OH CO2 C2H4 D CO2 C2H4 CH3OH

Question

Ethyl methanoate, HCOOC2H5, burns in excess oxygen to produce carbon dioxide and water. The equation is shown. 2HCOOC2H5 + xO2 → 6CO2 + 6H2O What is the value of x? A 2 B 7 C 9 D 18

Question

Rubidium is in Group I of the Periodic Table and bromine is in Group VII. Rubidium reacts with bromine to form an ionic compound. Which row shows the electron change taking place for rubidium and the correct formula of the rubidium ion? electron change formula of ion formed A electron gained Rb+ B electron gained Rb– C electron lost Rb+ D electron lost Rb–

Question

Which statement explains why graphite is used as a lubricant? A All bonds between the atoms are weak. B It conducts electricity. C It has a low melting point. D Layers in the structure can slide over each other.

Question

The relative atomic mass of chlorine is 35.5. When calculating relative atomic mass, which particle is the mass of a chlorine atom compared to? A a neutron B a proton C an atom of carbon-12 D an atom of hydrogen-1

Question

Universal indicator solution is added to a neutral solution of concentrated aqueous sodium chloride. The solution, which contains H+ (hydrogen), Na+ (sodium), Cl – (chloride) and OH– (hydroxide) ions, is electrolysed. The product at the cathode is hydrogen gas and the product at the anode is chlorine gas. What happens to the colour of the indicator in the solution during electrolysis? A The colour changes from blue to green. B The colour changes from blue to red. C The colour changes from green to blue. D The colour changes from green to red.

Question

What is the empirical formula of an oxide of iron, formed by reacting 2.24 g of iron with 0.96 g of oxygen? A FeO B Fe2O C Fe2O3 D Fe3O4

Question

The combustion of methane is exothermic. CH4 + 2O2 → CO2 + 2H2O Which statement about this reaction is correct? A The energy needed to break the bonds in methane and oxygen is greater than the energy released in making new bonds in carbon dioxide and water. B The energy needed to break the bonds in methane and oxygen is less than the energy released in making new bonds in carbon dioxide and water. C The energy released in breaking bonds in methane and oxygen is greater than the energy needed to make new bonds in carbon dioxide and water. D The energy released in breaking bonds in methane and oxygen is less than the energy needed to make new bonds in carbon dioxide and water.

Question

Hydrogen reacts with oxygen in a fuel cell. 2H2 + O2 → 2H2O The reaction is exothermic. 286 kJ of energy is released for every mole of water formed. Which volume of hydrogen gas, measured at room temperature and pressure, would react with oxygen with the release of 7000 J of energy? A 587 cm3 B 1175 cm3 C 587 dm3 D 1175 dm3

Question

Which substance does not require oxygen in order to produce energy? A coal B hydrogen C natural gas 235 D U

Question

Nitrogen, N2, and hydrogen, H2, can be converted into ammonia, NH3, using a catalyst. What is the purpose of the catalyst? A to increase the amount of ammonia produced B to increase the rate of reaction C to reduce the amount of reactants needed D to reduce the rate of reaction

Question

Ammonia is produced by the Haber process. The equation is shown. N2(g) + 3H2(g) 2NH3(g) The forward reaction is exothermic. Which statement is correct? A Increasing pressure decreases the yield of ammonia, but speeds up the reaction. B Increasing temperature decreases the yield of ammonia, but speeds up the reaction. C Increasing the concentration of hydrogen and nitrogen results in a lower yield of ammonia. D Increasing the temperature increases the yield of ammonia and speeds up the reaction.

Question

During the manufacture of sulfuric acid, sulfur dioxide is converted to sulfur trioxide. 2SO2 + O2 → 2SO3 Which type of reaction is this? A displacement B neutralisation C oxidation D thermal decomposition

Question

The equation for a redox reaction is shown. 2FeSO4 + Cl 2 + H2SO4 → Fe2(SO4)3 + 2HCl Which element is reduced? A chlorine B iron C oxygen D sulfur

Question

The equation shows a reaction between aqueous hydrogen bromide and aqueous ammonia. HBr(aq) + NH3(aq) → NH4+(aq) + Br–(aq) Which statement describes the role of aqueous hydrogen bromide? A It is a catalyst. B It is a reducing agent. C It is a proton acceptor. D It is a proton donor.

Question

The equations for three reactions are shown. 1 Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) 2 2AgNO3(aq) + CuI2(aq) → Cu(NO3)2(aq) + 2AgI(s) 3 CuO(s) + H2SO4(aq) → CuSO4(aq) + H2O(l) Which reactions are suitable for making a salt by precipitation? A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

Question

Zinc oxide is an amphoteric oxide. Which row describes the reactions of zinc oxide? reaction reaction with alkalis with acids A B C D

Question

A student carries out an experiment to prepare pure magnesium sulfate crystals. The diagram shows the first stage of the preparation. stirrer magnesium carbonate dilute sulfuric acid He adds magnesium carbonate until no more reacts. Which process should he use for the next stage? A crystallisation B evaporation C filtration D neutralisation

Question

Which row about elements in the Periodic Table is correct? statement 1 statement 2 A two elements in the same group metals are on the have similar chemical properties left of the table B two elements in the same group metals are on the have similar chemical properties right of the table C two elements in the same period metals are on the have similar chemical properties left of the table D two elements in the same period metals are on the have similar chemical properties right of the table

Question

A new element oxfordium, Ox, was discovered with the following properties. electrical formula bonding in a solubility conduction of element molecule of Ox2 insoluble in water doesn’t conduct Ox2 Ox Ox In which group of the Periodic Table should the new element be placed? A Group III B Group V C Group VII D Group VIII

Question

A flammable gas needs to be removed from a tank at an industrial plant. For safety reasons, an inert gas is used. Which gas is suitable? A argon B hydrogen C methane D oxygen

Question

Transition elements can have variable oxidation states. Which pair of compounds shows a transition element in two different oxidation states? A Cr2O3 and Cr2(SO4)3 B Cu2O and CuCO3 C ZnS and ZnSO4 D NiO and Ni(NO3)2

Question

Which diagram best represents the structure of a substance that is a good conductor of electricity at 25 °C? A B C D – + – + + – + – – + – +

Question

Why is aluminium metal unreactive with air? A It is covered with a layer of oxide. B It is low in the reactivity series. C It is produced by electrolysis of its oxide. D It melts at a high temperature.

Question

The apparatus used for the extraction of aluminium oxide by electrolysis is shown. carbon anodes – + carbon lining solution of as cathode aluminium oxide in molten cryolite molten aluminium collects at the bottom Which equation represents a reaction taking place at the anode? A O + 2e– → O2– B 2O2– → O2 + 4e– C Al 3– → Al + 3e– D Al 3+ + 3e– → Al

Question

The results of tests on solid S and its aqueous solution are shown. tests on solid S tests on aqueous solution of S effect of aqueous effect of effect of heat sodium hydroxide aqueous ammonia brown gas given off, white ppt., soluble in white ppt., soluble in together with a gas which excess, giving a excess, giving a relights a glowing splint colourless solution colourless solution What is S? A aluminium nitrate B aluminium sulfate C zinc sulfate D zinc nitrate

Question

Part of the carbon cycle is shown. combustion Q R glucose CO2 plant CH4 P What are processes P, Q and R? P Q R A decomposition respiration photosynthesis B respiration photosynthesis decomposition C respiration decomposition photosynthesis D photosynthesis respiration decomposition

Question

The element sulfur is found in a number of different minerals. Which mineral contains the greatest percentage by mass of sulfur? A barite, BaSO4 B galena, PbS C gypsum, CaSO4 D pyrite, FeS2

Question

Which structure represents a molecule of ethanol? A B C D H H H H H H H O H C C H C C H C C O H H C C H H H H H H H O H

Question

Which structures are structural isomers of each other? 1 2 H H H H H H H H C C C C H H C C C H H H H H H H H C H H 3 4 H H H H H H H C C C H H C C C H H H H H H C H H C H H H A 1, 2, 3 and 4 B 1, 2 and 4 only C 1 and 3 only D 2 and 4 only

Question

Which molecule is not produced by an addition reaction of ethene? A CH3CH3 B CH2BrCH2Br C CH3CH2OH D CH3CH2CH3

Question

The flow chart shows the preparation of ethanol and some important chemistry of ethanol. fermentation process Y substance X ethanol carbon dioxide + substance Z What are X, Y and Z? X Y Z A yeast combustion oxygen B glucose combustion steam C glucose polymerisation water D yeast fermentation glucose

Question

Which statement about nylon and Terylene is correct? A Nylon and Terylene are made from monomers with C=C bonds. B Nylon and Terylene contain the same linkage. C Nylon is a polyester. D Terylene is made from two different monomers.

Question

Which diagram represents the structure of a protein? O O O O A C C N N C C H H O O O O B C C O O C C C O O O H O H O D N C N C N C H O 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 89–103 104 105 106 107 108 109 110 111 112 114 116 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.).