Chemistry 0620/12 May/June 2021: question paper and mark scheme

Question

Iodine changes directly from a grey solid to a purple gas when it is heated. What is the name of this process? A condensation B evaporation C separation D sublimation

Question

Some sugar is contaminated with glass. How is a sample of solid sugar obtained from the mixture? A dissolve in water and then evaporate B dissolve in water, then filter and then dry the solid residue C dissolve in water, then filter and evaporate the filtrate D dissolve in water and then distil

Question

Which statement about paper chromatography is correct? A A solvent is needed to dissolve the paper. B Paper chromatography separates mixtures of solvents. C The solvent should cover the baseline. D The baseline should be drawn in pencil.

Question

Element X has 7 protons. Element Y has 8 more protons than X. Which statement about element Y is correct? A Y has more electron shells than X. B Y has more electrons in its outer shell than X. C Y is in a different group of the Periodic Table from X. D Y is in the same period of the Periodic Table as X.

Question

A covalent molecule Q contains only six shared electrons. What is Q? A ammonia, NH3 B chlorine, Cl 2 C methane, CH4 D water, H2O

Question

What is the formula of the product of burning sodium in chlorine gas? A NaCl B Na2Cl C NaCl 2 D Na2Cl 2

Question

Chemical compounds formed from a Group I element and a Group VII element contain ionic bonds. How are the ionic bonds formed? A Electrons are transferred from Group VII atoms to Group I atoms. B Electrons are shared between Group I atoms and Group VII atoms. C Electrons are lost by Group I atoms and Group VII atoms. D Electrons are transferred from Group I atoms to Group VII atoms.

Question

Some information about particles P, Q, R and S is shown. nucleon number of number of number neutrons electrons P 12 6 6 Q 24 12 10 R 16 8 10 S 14 8 6 Which two particles are isotopes of the same element? A P and Q B P and S C Q and R D R and S

Question

What is the relative formula mass of magnesium nitrate, Mg(NO3)2? A 74 B 86 C 134 D 148

Question

In separate experiments, electricity was passed through concentrated aqueous sodium chloride and molten lead(II) bromide. What would happen in both experiments? A A halogen would be formed at the anode. B A metal would be formed at the cathode. C Hydrogen would be formed at the anode. D Hydrogen would be formed at the cathode.

Question

A reaction involving aluminium is shown. xAl + yO2 + 6H2O → xAl (OH)3 Which values of x and y balance the equation? x y A 2 3 B 3 2 C 3 4 D 4 3

Question

Four different fuels are used to heat a beaker of water, for the same amount of time, using the apparatus shown. thermometer stirrer screen to reduce draughts 200 g of water spirit burner fuel The initial temperature of the water and the temperature after heating by the fuel are recorded. Which fuel releases the most heat energy? initial temperature temperature after / °C heating / °C A 17 46 B 24 52 C 26 61 D 30 62

Question

Which substance is not used as a fuel? A ethanol B hydrogen C methane D oxygen

Question

When sulfur is heated it undergoes a ……1…… change as it melts. Further heating causes the sulfur to undergo a ……2…… change and form sulfur dioxide. Which words complete gaps 1 and 2? 1 2 A chemical chemical B chemical physical C physical chemical D physical physical

Question

An excess of calcium carbonate reacts with dilute hydrochloric acid. The volume of carbon dioxide produced is measured at regular time intervals. The results are shown as experiment 1. The experiment is repeated with only one change to the reaction conditions. The results are shown as experiment 2. experiment 2 experiment 1 volume of CO2 time Which change is made in experiment 2? A The concentration of the acid is increased. B The volume of acid is increased. C The mass of calcium carbonate is increased. D The calcium carbonate is powdered.

Question

The equation represents a reaction that can be reversed by changing the conditions. anhydrous cobalt(II) chloride + water hydrated cobalt(II) chloride blue pink Which statement is correct? A When anhydrous cobalt(II) chloride is heated, water vapour is produced. B Blue cobalt(II) chloride paper turns pink when placed in water vapour. C Anhydrous cobalt(II) chloride paper is pink and turns blue when placed in water. D The colour changes from blue to pink when hydrated cobalt(II) chloride is heated.

Question

Which statements about acids are correct? 1 They react with carbonates to form carbon dioxide. 2 They react with metals to form hydrogen. 3 They react with ammonium salts to form ammonia. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Element X forms an oxide, XO, that neutralises sulfuric acid. Which row describes X and XO? element X nature of oxide, XO A metal acidic B metal basic C non-metal acidic D non-metal basic

Question

Which test for the named gas is correct? A Oxygen extinguishes a lighted splint. B Hydrogen relights a glowing splint. C Ammonia turns blue litmus red. D Carbon dioxide turns limewater milky.

Question

Three tests are done to identify the ions present in aqueous solution X. test test result dilute nitric acid, followed by aqueous silver nitrate cream precipitate aqueous sodium hydroxide white precipitate, soluble in excess aqueous ammonia white precipitate, soluble in excess Which ions are present in X? A Al 3+ and Br – B Al 3+ and I– C Zn2+ and Br – D Zn2+ and I–

Question

Part of the Periodic Table is shown. Which element is a non-metal with the lowest melting point? C B A D

Question

Period 3 of the Periodic Table contains the elements sodium to argon. Which statement about the elements is correct? A Na and Mg are poor conductors of electricity. B Na and Mg react with acids to make hydrogen. C S and Cl are malleable and ductile. D S and Cl have the highest melting and boiling points.

Question

The diagram shows the positions of elements E, F, G and H in the Periodic Table. G H E F Which statements about elements E, F, G and H are correct? 1 E has a higher density than F. 2 E has a higher melting point than F. 3 G has a darker colour than H. 4 G has a lower melting point than H. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

An element melts at 1455 °C, has a density of 8.90 g / cm3 and forms a green chloride. Where in the Periodic Table is this element found? A B C D

Question

The noble gases are placed in Group VIII of the Periodic Table. Which statement explains why they are unreactive? A They have eight electrons in their outer shell. B They have a full outer shell of electrons. C They have even numbers of neutrons. D They have even numbers of protons.

Question

Iron from a blast furnace is treated with oxygen and with calcium oxide to make steel. Which substances in the iron are removed? oxygen calcium oxide removes removes A carbon acidic oxides B carbon basic oxides C iron acidic oxides D iron basic oxides

Question

Cobalt, manganese and chromium are all metals. ● Cobalt(II) oxide reacts with carbon to form cobalt metal. ● Manganese(II) oxide does not react with carbon. ● Chromium(II) oxide does not react with carbon. ● Chromium does not react with water. ● Manganese reacts with water. What is the order of reactivity of these metals? least most reactive reactive A cobalt chromium manganese B cobalt manganese chromium C chromium manganese cobalt D manganese chromium cobalt

Question

Iron is extracted from hematite. Aluminium is extracted from bauxite. Which statements about the extraction processes are correct? 1 Both involve reduction. 2 Both take place at high temperature. 3 Both involve electrolysis. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Which property of aluminium makes it useful for food containers? A It conducts heat. B It has low density. C It is strong. D It resists corrosion.

Question

Which substance is essential for iron nails to rust? A carbon dioxide B hydrogen C nitrogen D oxygen

Question

Which row describes the uses of sulfur and sulfur dioxide? sulfur sulfur dioxide A extraction of aluminium food preservative B extraction of aluminium manufacture of cement C manufacture of sulfuric acid food preservative D manufacture of sulfuric acid manufacture of cement

Question

Which substance is a diatomic covalent molecule found in pure dry air? A argon B carbon dioxide C nitrogen D hydrogen

Question

The equations represent two reactions, P and Q, of lime (calcium oxide). P CaO + SiO2 → CaSiO3 Q CaO + SO2 → CaSO3 In which processes do the reactions occur? P Q A extraction of iron extraction of iron B extraction of iron flue gas desulfurisation C flue gas desulfurisation extraction of iron D flue gas desulfurisation flue gas desulfurisation

Question

Which gas is the main constituent of natural gas? A ethane B ethene C methane D propane

Question

Which compounds belong to the same homologous series? A ethane and propane B ethanoic acid and ethanol C methane and ethene D propene and ethanoic acid

Question

Which statement about alkanes is correct? A They burn in oxygen. B They contain carbon, hydrogen and oxygen atoms. C They contain double bonds. D They contain ionic bonds.

Question

Which compound decolourises aqueous bromine? A B C D H H H H H H H H H H H C C H H C C C H C C O H H C C C H H H H H H H H H H

Question

What is the chemical equation for the process of fermentation? A C6H12O6 + 6O2 → 6CO2 + 6H2O B C6H12O6 → 2C2H5OH + 2CO2 C C6H12O6 + 3H2O → 3C2H5OH + 3O2 D C6H12O6 + 3O2 → 6CO + 6H2O

Question

The flow chart shows how petroleum may be turned into a plastic. process process process 1 saturated 2 unsaturated 3 petroleum plastic hydrocarbon hydrocarbon What are processes 1, 2 and 3? process 1 process 2 process 3 A cracking fractional distillation polymerisation B cracking polymerisation fractional distillation C fractional distillation cracking polymerisation D fractional distillation polymerisation cracking

Question

Which substance is a natural polymer? A ethene B Terylene C nylon D protein 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.).