Chemistry 0620/22 May/June 2023: question paper and mark scheme

Question

Four physical changes of ethanol are listed. 1 condensation 2 evaporation 3 freezing 4 boiling In which changes do the particles move further apart? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Question

An atom of element X contains: ● 5 protons ● 6 neutrons ● 5 electrons. Which statements about element X are correct? 1 X has an atomic number of 6. 2 X has a nucleon number of 11. 3 X is in Group II of the Periodic Table. 4 X is in the second period of the Periodic Table. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Ammonia, NH3, is a covalent molecule. Which diagram shows the outer-shell electron arrangement in a molecule of ammonia? A B H N H H N H H H C D H N H H N H H H

Question

Which structure does silicon(IV) oxide most closely resemble? A carbon dioxide B diamond C graphite D sodium chloride

Question

Substance P conducts electricity when solid. Which particles move in solid P so that it can conduct electricity? 1 anions 2 cations 3 electrons A 1 and 2 B 1 only C 2 and 3 D 3 only

Question

Which equation represents a chemical change? A BaCl 2(s) → BaCl 2(l) B Ca2+(aq) + SO42–(aq) → CaSO4(s) C KCl (s) + H2O(l) → K+(aq) + Cl –(aq) D Na+(aq) + NO3–(aq) → NaNO3(aq)

Question

Which sample contains the largest number of molecules? A 16 g of methane, CH4(g) B 16 g of oxygen, O2(g) C 16 g of phosphorus, P4(s) D 16 dm3 of methane at r.t.p., CH4(g)

Question

The concentration of a sample of dilute aqueous sodium hydroxide is found by titration. The apparatus used is shown. dilute aqueous hydrochloric acid, HCl (aq) dilute aqueous sodium hydroxide, NaOH(aq) Which information is needed to calculate the concentration of the dilute aqueous sodium hydroxide in mol / dm3? concentration volume of molar mass volume of molar mass of HCl HCl used of HCl NaOH used of NaOH A B C D key = needed = not needed

Question

In experiment 1, aqueous copper(II) sulfate is electrolysed using graphite electrodes. In experiment 2, aqueous copper(II) sulfate is electrolysed using copper electrodes. Which statement identifies a half-equation for a reaction at one of the electrodes? A In experiment 1, the half-equation for the anode reaction is 4OH– → 2H2O + O2 + 4e–. B In experiment 1, the half-equation for the cathode reaction is 2H+ + 2e– → H2. C In experiment 2, the half-equation for the anode reaction is Cu2+ + 2e– → Cu. D In experiment 2, the half-equation for the cathode reaction is 4OH– → 2H2O + O2 + 4e–.

Question

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

Question

Methane burns in excess oxygen. The equation is shown. CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) Bond energies are shown. bond energy bond in kJ / mol C=O 805 C–H 410 O=O 496 O–H 460 What is the energy change for the reaction? A (4 × 410 + 2 × 496) – (2 × 805 + 4 × 460) B (2 × 805 + 4 × 460) – (4 × 410 + 2 × 496) C (410 + 2 × 496) – (805 + 2 × 460) D (410 + 496) – (805 + 460)

Question

Which change increases the rate of reaction by decreasing the activation energy, Ea? A addition of a catalyst B decrease in size of solid reactants C increase in concentration of solutions D increase in temperature

Question

In the Contact process, sulfur dioxide is reacted with oxygen to form sulfur trioxide. Which conditions are used in this reaction? temperature pressure catalyst / °C / kPa A 300 200 iron B 300 20 000 vanadium(V) oxide C 450 200 vanadium(V) oxide D 450 20 000 iron

Question

Which reaction is reversible? A an iron nail rusting when left in moist air B limestone reacting with an acid to form carbon dioxide gas C magnesium burning in air to produce a white ash D white anhydrous copper(II) sulfate turning blue when water is added

Question

The equation for the reaction of sulfur dioxide with acidified potassium dichromate(VI) is shown. 3SO2 + Cr2O72– + 2H+ → 3SO42– + 2Cr3+ + H2O What is oxidised and what is the oxidising agent? oxidised oxidising agent A SO2 Cr2O72– B SO2 H+ C Cr2O72– H+ D Cr2O72– Cr2O72–

Question

What is the definition of a strong acid? A a proton acceptor that is completely dissociated in aqueous solution B a proton acceptor that is partially dissociated in aqueous solution C a proton donor that is completely dissociated in aqueous solution D a proton donor that is partially dissociated in aqueous solution

Question

Which statement about amphoteric oxides is correct? A They are made by combining an acidic oxide with a basic oxide. B They react with water to give a solution of pH 7. C They react with both acids and bases. D They do not react with acids or bases.

Question

Copper(II) carbonate is formed when aqueous sodium carbonate is added to aqueous copper(II) nitrate. The ionic equation for the reaction is shown. CO32–(aq) + Cu2+(aq) → CuCO3(s) How is pure copper(II) carbonate obtained from the reaction mixture? A evaporate → filter → dry B evaporate → wash → crystallise C filter → evaporate → crystallise D filter → wash → dry

Question

Q and R are elements in the same period of the Periodic Table. Q has 7 electrons in its outer shell and R has 2 electrons in its outer shell. Which statement about Q and R is correct? A Q is a metal and R is a non-metal. B Q and R have different numbers of electron shells. C R is found to the right of Q in the Periodic Table. D The proton number of R is less than the proton number of Q.

Question

Lead(II) sulfate is an insoluble salt. Which reaction produces a mixture from which lead(II) sulfate is obtained by filtration? A adding solid lead(II) carbonate to dilute sulfuric acid B adding solid lead(II) hydroxide to dilute sulfuric acid C adding metallic lead to dilute sulfuric acid D adding aqueous lead(II) nitrate to dilute sulfuric acid

Question

Which statement about alkali metals is correct? A Lithium is more dense than sodium. B Sodium is more reactive than potassium. C Sodium has a higher melting point than potassium. D They are in Group II of the Periodic Table.

Question

Which row describes the properties of a transition element? melting forms coloured density point compounds A high low no B high high yes C low low no D low low yes

Question

Which row identifies the properties of zinc? thermal reacts with conductivity dilute acid A good yes B good no C poor yes D poor no

Question

Uses of metals depend on their properties. Which property is necessary for the use given? use of the metal property of the metal A car bodies ductile B cutlery conducts heat C food containers resists corrosion D overhead electrical cables high density

Question

Which compounds both contribute to acid rain? A carbon monoxide and carbon dioxide B carbon monoxide and oxides of nitrogen C oxides of nitrogen and sulfur dioxide D sulfur dioxide and carbon dioxide

Question

P, Q, R and S are metals. P reacts with dilute hydrochloric acid, forming hydrogen. Q reacts violently with water. R reacts with water to give hydrogen. S is formed by heating its oxide with carbon. Which row identifies the metals? P Q R S A copper sodium potassium iron B zinc magnesium calcium iron C zinc sodium calcium magnesium D iron potassium sodium zinc

Question

Which compound is formed when iron rusts? A anhydrous iron(II) oxide B anhydrous iron(III) oxide C hydrated iron(III) hydroxide D hydrated iron(III) oxide

Question

Why is cryolite used in the extraction of aluminium by electrolysis? A It dissolves the aluminium oxide. B It protects the anodes from corrosion. C It changes bauxite to aluminium oxide. D It decreases the melting point of the aluminium.

Question

A wax candle is made from a mixture of hydrocarbons. The candle is lit and placed in a gas jar along with a strip of cobalt(II) chloride test paper as shown. cobalt(II) chloride paper gas jar combustion products wax candle After a short time, the oxygen in the jar is used up and the candle flame goes out. Which substance does the cobalt(II) chloride paper identify? A carbon dioxide B carbon monoxide C sulfur dioxide D water

Question

The hydrocarbon C4H8 has two structural isomers, but-1-ene and but-2-ene. Which statement is correct? A But-2-ene has the structural formula CH3CH=CHCH3 and the same general formula as butane. B But-2-ene has the structural formula CH3CH=CHCH3 and the same empirical formula as ethene. C But-1-ene has the structural formula CH3CH2CH=CH2 and the same general formula as butane. D But-1-ene has the structural formula CH3CHCH2=CH and the same empirical formula as ethene.

Question

Which compound rapidly decolourises aqueous bromine? A propane B propanoic acid C propanol D propene

Question

What are the products of the addition reactions of ethene with bromine and hydrogen? bromine hydrogen A CH2BrCH2Br CH3CH3 B CH2BrCH2Br CH2CH2 C CH3CH2Br CH3CH3 D CH3CH2Br CH2CH2

Question

Ethanol is manufactured by fermentation and the catalytic addition of steam to ethene. Which row describes an advantage of both methods? from sugar by fermentation from ethene and steam A ethanol needs to be purified the process is continuous B it is a batch process ethene comes from petroleum C the process is slow the process is rapid D renewable resources are used the ethanol produced is pure

Question

Methanoic acid and propan-1-ol react to form an ester. What is the structural formula of the ester? A HCOOCH2CH2CH3 B CH3CH2COOCH3 C CH3COOCH2CH3 D CH3CH2CH2COOH

Question

What is the correct structure of PET? O O H O O A C C N N C C N N H H H O O O O B C C O O C C O O O O H O O H C C C N N C C N N H H O O O O D C C O C O C O

Question

Alkanes undergo substitution reactions in the presence of UV light. Which equation represents a substitution reaction of ethane? A C2H6 + Cl 2 → C2H4 + 2HCl B C2H6 + Cl 2 → C2H5Cl + HCl C C2H6 + Cl 2 → C2H4Cl 2 + H2 D C2H6 + HCl → C2H5Cl + H2

Question

Methane reacts with chlorine in substitution reactions. How many different products, containing a single carbon atom, can be made during the reactions? A 2 B 3 C 4 D 5

Question

Rock salt is a mixture of salt and sand. The method used to separate the sand from the salt is listed. step 1 Crush the rock salt, add to warm water and stir. step 2 Pour the mixture through a filter paper held in a funnel. step 3 Evaporate the water to crystallise the salt. Which statement about the method is correct? A The filtrate in step 2 is pure water. B The residue in step 2 is pure crystals of salt. C The solute is salt. D The solvent is a mixture of salt and water.

Question

Two compounds, M and N, are dissolved in water and separated by chromatography. The results are shown. solvent front N 10 cm M 2 cm baseline What is the Rf value of M and which compound is most soluble in water? most soluble Rf value of M compound A 0.2 M B 0.2 N C 5.0 M D 5.0 N

Question

When acid is added to salt X, a gas is produced which turns limewater milky. When sodium hydroxide is added to salt X, a gas is produced which turns litmus paper blue. What is X? A CaCO3 B (NH4)2CO3 C NH4NO3 D ZnCO3 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 89–103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 actinoids Fr Ra Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og francium radium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson – – – – – – – – – – – – – – – – – 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.).