Chemistry 0620/21 May/June 2021: question paper and mark scheme

Question

A gas is released at point P in the apparatus shown. P damp universal indicator paper Which gas turns the damp universal indicator paper red most quickly? A ammonia, NH3 B chlorine, Cl 2 C hydrogen chloride, HCl D sulfur dioxide, SO2

Question

A mixture is separated using the apparatus shown. mixture funnel filter paper What is the mixture? A aqueous copper(II) sulfate and aqueous sodium chloride B aqueous copper(II) sulfate and copper C copper and sulfur D ethanol and ethanoic acid

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

The arrangement of particles in each of two solids, S and T, are shown. S T What are S and T? S T A diamond silicon(IV) oxide B diamond sodium chloride C graphite silicon(IV) oxide D graphite sodium chloride

Question

Which statement about metals is correct? A Metals conduct electricity when molten because negative ions are free to move. B Metals conduct electricity when solid because positive ions are free to move. C Metals are malleable because the bonds between the atoms are weak. D Metals are malleable because the layers of ions can slide over each other.

Question

Two elements, P and Q, are in the same period of the Periodic Table. P and Q react together to form an ionic compound. Part of the lattice of this compound is shown. P+ Q– Q– P+ Q– P+ P+ Q– Which statement is correct? A An ion of P has more electrons than an ion of Q. B Element P is non-metallic. C P is to the left of Q in the Periodic Table. D The formula of the compound is P4Q4.

Question

2.56 g of a metal oxide, MO2, is reduced to 1.92 g of the metal, M. What is the relative atomic mass of M? A 48 B 96 C 128 D 192

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

What is the ionic half-equation for the reaction that occurs at the cathode when molten lead(II) bromide is electrolysed? A Pb2+ + 2e– → Pb B 2Br – → Br2 + 2e– C Br2 + 2e– → 2Br – D Pb → Pb2+ + 2e–

Question

The complete combustion of propane is exothermic. The equation for this reaction is shown. C3H8 + 5O2 → 3CO2 + 4H2O Which energy level diagram represents the complete combustion of propane? A B C3H8 + 5O2 3CO2 + 4H2O energy energy 3CO2 + 4H2O C3H8 + 5O2 progress of reaction progress of reaction C D 3CO2 + 4H2O C3H8 + 5O2 energy energy C3H8 + 5O2 3CO2 + 4H2O progress of reaction progress of reaction

Question

Which equation represents a reaction that takes place in a fuel cell? A C + O2 → CO2 B 2H2 + O2 → 2H2O C CH4 + 2O2 → CO2 + 2H2O D C3H8 + 5O2 → 3CO2 + 4H2O

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

Four statements about the effect of increasing temperature on a reaction are shown. 1 The activation energy becomes lower. 2 The particles move faster. 3 There are more collisions between reacting particles per second. 4 There are more collisions which have energy greater than the activation energy. Which statements are correct? A 1, 2 and 3 B 1, 3 and 4 C 2, 3 and 4 D 2 and 3 only

Question

An example of a redox reaction is shown. Zn + Cu2+ → Zn2+ + Cu Which statement about the reaction is correct? A Zn is the oxidising agent and it oxidises Cu2+. B Zn is the oxidising agent and it reduces Cu2+. C Zn is the reducing agent and it oxidises Cu2+. D Zn is the reducing agent and it reduces Cu2+.

Question

Which statement about a reaction in equilibrium is correct? A Both the forward and the backward reactions are proceeding at the same rate. B Neither the forward nor the backward reaction is proceeding. C The amount of product present is no longer affected by changes in temperature or pressure. D The amount of product present is only affected by a change in pressure.

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

Copper(II) sulfate is prepared by adding excess copper(II) oxide to warm dilute sulfuric acid. Which purification methods are used to obtain pure solid copper(II) sulfate from the reaction mixture? 1 crystallisation 2 filtration 3 chromatography 4 distillation A 1 and 4 B 1 and 2 C 2 and 3 D 3 and 4

Question

Some reactions of element M are shown. burn add water element M oxide of M solution add to purple acidified add blue litmus potassium manganate(VII) goes colourless goes red What is element M? A carbon B iron C magnesium D sulfur

Question

In which equation is the underlined reactant acting as a base? A CH3COO– + H3O+ → CH3COOH + H2O B NH4+ + OH– → NH3 + H2O C CO2 + 2H2O → H3O+ + HCO3– D H+ + OH– → H2O

Question

Why is helium used to fill balloons? A Helium is monoatomic. B Helium is in Group VIII of the Periodic Table. C Helium has a full outer electron shell. D Helium is less dense than air.

Question

Which elements in the table are transition elements? element property E forms E3+ ions only F forms F+ and F2+ ions G forms only white salts H used in catalytic converters A E and G B E and H C F and G D F and H

Question

Element R forms a covalent compound R2Si with silicon. Which row describes R? metallic or group number in non-metallic character the Periodic Table A metallic II B metallic VI C non-metallic II D non-metallic VI

Question

Some properties of metal J are listed. ● J does not react with cold water. ● J reacts with dilute hydrochloric acid. ● No reaction occurs when the oxide of J is heated with carbon. What is J? A copper B iron C magnesium D sodium

Question

Some metal nitrates and carbonates decompose when heated strongly. Metal Q has a nitrate that decomposes to give a salt and a colourless gas only. The carbonate of metal Q does not decompose when heated with a Bunsen burner. What is metal Q? A calcium B copper C sodium D zinc

Question

Which substances are used in the extraction of aluminium? A bauxite and cryolite B bauxite and hematite C cryolite and zinc blende D hematite and zinc blende

Question

Different types of steel alloys are manufactured by changing the percentage of carbon in the alloy. The properties of four steel alloys are shown. alloy percentage of strength of hardness of mixture carbon in the alloy the alloy the alloy 1 0.00 to 0.20 high low 2 0.21 to 0.30 high medium 3 0.31 to 0.40 medium high 4 0.41 to 1.50 low high What are the properties of the steel alloy containing 0.23% of carbon? strength hardness A high low B low high C high medium D medium high

Question

Ammonia is made by reacting nitrogen with hydrogen in the Haber process. The equation for the process is shown. N2 + 3H2 2NH3 Which changes in reaction conditions would produce a greater yield of ammonia? 1 adding more iron catalyst 2 increasing the reaction pressure 3 increasing the particle size of the iron catalyst A 1 only B 2 only C 1 and 2 D 2 and 3

Question

Which process removes carbon dioxide from the atmosphere? A combustion of fossil fuels B fermentation C photosynthesis D respiration

Question

Which catalyst is used in the Contact process? A calcium oxide B iron C manganese(II) oxide D vanadium(V) oxide

Question

A white solid Z reacts with dilute hydrochloric acid to produce a gas. The same gas is produced when compound Z is heated strongly. What is Z? A calcium B calcium carbonate C calcium hydroxide D calcium oxide

Question

What is the structure of butanoic acid? A CH3CH2CO2H B CH3CH2CH2CO2H C CH3CH2CH2CH2CO2H D CH3CH2CH2CO2CH3

Question

Compound Z contains carbon, hydrogen and oxygen. Molecules of compound Z have four hydrogen atoms and two carbon atoms. Compound Z can be made by oxidation of an alcohol. What is compound Z? A ethene B ethanol C ethanoic acid D methyl methanoate

Question

Which statement about homologous series and isomerism is correct? A Butane and butene are structural isomers. B Compounds in the same homologous series have the same general formula. C Compounds in the same homologous series have the same molecular formula. D Structural isomers have different molecular formulae.

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

What is an advantage of manufacturing ethanol by fermentation? A The process is very fast. B The ethanol requires no separation. C The raw materials used are renewable. D There are no other products formed.

Question

P, Q, R and S are four organic compounds. P is an unsaturated hydrocarbon. Q burns but otherwise is unreactive. R contains a C–C single bond and a C=C double bond. S undergoes addition polymerisation. Which compounds are alkenes? A P and R only B P, R and S C P, Q and S D Q, R and S

Question

The structure of a synthetic polymer is shown. O O O O O C C N N C C N N C H H H H The structure shows that it is a ……1…… . It is formed by ……2…… polymerisation. Which words complete gaps 1 and 2? 1 2 A polyamide addition B polyamide condensation C polyester addition D polyester condensation

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.).