Chemistry 0620/22 February/March 2020: question paper and mark scheme

Question

The formula of methane is CH4 and the formula of ethane is C2H6. Which row describes diffusion and the relative rates of diffusion of methane and ethane? description of diffusion relative rate of diffusion A particles move from ethane diffuses more a high concentration quickly than methane to a low concentration B particles move from methane diffuses more a high concentration quickly than ethane to a low concentration C particles move from ethane diffuses more a low concentration quickly than methane to a high concentration D particles move from methane diffuses more a low concentration quickly than ethane to a high concentration

Question

Which test is used to show that a sample of water is pure? A Evaporate the water to see if any solids remain. B Heat the water to check its boiling point. C Test with anhydrous cobalt(II) chloride. D Use universal indicator paper to check its pH.

Question

Chromatography is used to separate and identify the components in both coloured and colourless mixtures. For colourless mixtures the chromatogram has to be treated with another chemical. What is the name of this type of chemical? A colouring agent B display agent C finding agent D locating agent

Question

Lithium reacts with fluorine to form the compound lithium fluoride. Which statement about this reaction is correct? A Each fluorine atom gains one electron. B Each fluorine atom gains two or more electrons. C Each fluorine atom loses one electron. D Each fluorine atom loses two or more electrons. 14 12

Question

6 C and 6 C are isotopes of carbon. Which statement about these isotopes is correct? 12 14 A 6 C is more reactive than 6 C because the atoms have less mass. 12 14 B 6 C is more reactive than 6 C because the atoms have different numbers of neutrons. C The reactions of 126 C are similar to 146 C because they have the same number of outer shell electrons. D The reactions of 126 C are similar to 146 C because they have the same number of protons in the nucleus.

Question

The molecular structure of hydrazine, N2H4, is shown. H H N N H H Which description of the bonding in hydrazine is not correct? A Each nitrogen atom has a non-bonding pair of electrons. B Each nitrogen atom has four bonding pairs of electrons. C Each nitrogen atom shares one of its electrons with a nitrogen atom. D Each nitrogen atom shares two of its electrons with hydrogen atoms.

Question

Solid X has a high boiling point. Its structure has positive ions surrounded by a sea of electrons. Which other properties does solid X have? A brittle and an electrical conductor B brittle and an insulator C malleable and an electrical conductor D malleable and an insulator

Question

The formulae of some ions are shown. positive ions negative ions Al 3+ Cl – Fe2+ N3– Mg2+ NO3– Na+ O2– Zn2+ SO42– In which row is the formula not correct? compound formula A aluminium oxide Al 2O3 B iron(II) nitride Fe2N3 C sodium sulfate Na2SO4 D zinc nitrate Zn(NO3)2

Question

The equation for the decomposition of magnesium nitrate is shown. 2Mg(NO3)2(s) → 2MgO(s) + 4NO2(g) + O2(g) Which volume of gas is produced when 0.1 moles of magnesium nitrate is decomposed completely? A 1.2 dm3 B 4.8 dm3 C 6.0 dm3 D 8.4 dm3

Question

Which statements about the electrolysis of molten lead(II) bromide are correct? 1 Lead ions move to the anode and are oxidised. 2 Lead ions move to the cathode and are reduced. 3 Bromide ions move to the anode and are oxidised. 4 Bromide ions move to the cathode and are reduced. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Aqueous copper(II) sulfate is electrolysed using carbon electrodes. Which statement is correct? A Bubbles of hydrogen are formed at the anode. B Bubbles of oxygen gas are formed at the cathode. C Copper is deposited at the anode. D The blue colour of the solution fades.

Question

Nitrogen trifluoride, NF3, is used in the manufacture of certain types of solar panels. The equation for the formation of nitrogen trifluoride is shown. N2 + 3F2 → 2NF3 type of bond bond energy (kJ mol–1) N≡N +950 F–F +150 N–F +280 Using the table of bond energies, what is the energy change for this reaction? A –560 kJ mol–1 B –280 kJ mol–1 C +280 kJ mol–1 D +3080 kJ mol–1

Question

Which statements about hydrogen fuel cells are correct? 1 The reaction between hydrogen and oxygen is endothermic. 2 The waste product in a hydrogen fuel cell is water. 3 A chemical reaction in the cell produces hydrogen which is used as the fuel. 4 A hydrogen fuel cell is used to generate electricity. A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Question

Which change is a physical change? A Copper(II) carbonate changes colour from green to black when it is heated, and stays black when it cools. B Ethanol reacts with oxygen to form carbon dioxide and water. C Hydrogen peroxide decomposes into water and oxygen when it is boiled. D Ice forms liquid water when it is heated.

Question

A student adds excess magnesium ribbon to 10 cm3 of 0.5 mol / dm3 sulfuric acid. The hydrogen gas is collected and its volume measured every 10 seconds. The experiment is repeated using the same mass of magnesium ribbon with 5 cm3 of 0.5 mol / dm3 sulfuric acid added to 5 cm3 of water. Which graph shows the results of the second experiment? 250 A 200 150 original experiment volume of B hydrogen / cm3 100 C 50 D 0 0 50 100 150 200 250 time / seconds

Question

An equilibrium reaction is shown. N2O4(g) 2NO2(g) The forward reaction is endothermic. What is the effect of changing the temperature and pressure on the equilibrium position? increasing temperature increasing pressure A moves to the left moves to the left B moves to the left moves to the right C moves to the right moves to the left D moves to the right moves to the right

Question

In which reaction is the underlined compound acting as a reducing agent? A CO2 + C → 2CO B 2CuO + C → 2Cu + CO2 C Fe2O3 + 3CO → 2Fe + 3CO2 D CaCO3 + 2HCl → CaCl 2 + H2O + CO2

Question

X, Y and Z are oxides of elements in the same row of the Periodic Table. Some information about each oxide is shown. ability to ability to solubility oxide neutralise neutralise in water an acid an alkali X soluble key Y insoluble = able Z slightly soluble = not able Which types of oxides are X, Y and Z? X Y Z A acidic amphoteric basic B amphoteric basic basic C basic amphoteric acidic D basic acidic amphoteric

Question

Four different acids are dissolved in water. Which beaker contains the most concentrated strong acid solution? A B Z– Z– HY Y– HY H+ H+ H+ Z – Z– HY H+ HY H+ H+ Y– Z– H+ HY Z– + HY H C D X– H+ HX H+ W– HX H+ HX X– HX W– – W– X HX HX H+ + H HX H+ H+ HX W–

Question

The following substances can be reacted together to prepare salts. 1 copper(II) oxide and excess hydrochloric acid 2 hydrochloric acid and excess sodium hydroxide 3 hydrochloric acid and excess zinc carbonate In which reactions can the excess reactant be separated from the solution by filtration? A 1 and 2 B 1 and 3 C 2 and 3 D 3 only

Question

Salt S is dissolved in water and three tests are carried out on the solution. test result 1 aqueous sodium green precipitate formed, hydroxide is added insoluble in excess sodium hydroxide 2 dilute nitric acid is added no reaction 3 aqueous barium nitrate is added white precipitate formed to the acidified solution from test 2 What is the identity of S? A copper(II) chloride B copper(II) sulfate C iron(II) chloride D iron(II) sulfate

Question

Which statement about the Periodic Table is correct? A Most metallic elements are on the left. B Elements in the same period have the same number of outer electrons. C Elements on the left are usually gases. D The relative atomic mass of the elements increases from right to left.

Question

The diagram shows elements W, X, Y and Z in a section of the Periodic Table. W X Z Y Which statement about the reactivity of the elements is correct? A X is more reactive than Y, and W is more reactive than Z. B X is more reactive than Y, and Z is more reactive than W. C Y is more reactive than X, and W is more reactive than Z. D Y is more reactive than X, and Z is more reactive than W.

Question

Some properties of substances are listed. 1 They conduct electricity. 2 They have low densities. 3 They have high melting points. 4 They are malleable. Which properties are shown by transition metals? A 1 and 3 only B 1 and 4 only C 1, 2 and 3 D 1, 3 and 4

Question

Sodium is a Group I metal. Which property, that is typical of most metals, is not shown by sodium? A conductor of heat B high melting point C malleable D shiny

Question

Four metals, iron, copper, magnesium and Y, are heated separately with their oxides. The results are shown. magnesium Y copper iron metal oxide oxide oxide oxide Y key magnesium = reacts copper = no reaction iron What is the order of reactivity of the metals, least reactive first? least reactive most reactive A copper iron Y magnesium B copper Y iron magnesium C magnesium iron Y copper D magnesium Y iron copper

Question

Aluminium is extracted from bauxite by electrolysis. Which statement is correct? A Aluminium ions are oxidised to form aluminium. B The cathode has to be replaced regularly because it reacts with the oxygen which is formed. C Cryolite is added to remove impurities. D Carbon dioxide is produced at the anode.

Question

Some properties of aluminium are listed. 1 It conducts heat. 2 It has a low density. 3 It is strong. 4 It is resistant to corrosion. Which of these properties make aluminium suitable for making food containers for chilled food products? A 1, 2 and 4 B 1, 3 and 4 C 1 only D 4 only

Question

Water is treated at a waterworks to make it fit to drink. What is present in the water when it leaves the waterworks? A bacteria only B bacteria and insoluble substances C chlorine compounds only D chlorine compounds and soluble substances

Question

Sulfur dioxide, carbon monoxide and oxides of nitrogen are common gaseous pollutants found in the air. Which pollutants contribute to acid rain? A carbon monoxide and sulfur dioxide B oxides of nitrogen and sulfur dioxide C oxides of nitrogen only D sulfur dioxide only

Question

Oxides of nitrogen, such as NO and NO2, are formed in the petrol engines of cars. They are removed from the exhaust gases by reactions in the car’s catalytic converter. Which row describes how oxides of nitrogen are formed in a petrol engine, and a reaction that happens in the catalytic converter? a reaction that happens how oxides of nitrogen are formed in the catalytic convertor A by the reaction between 2NO + 2CO → N2 + 2CO2 nitrogen and oxygen from the air B by the reaction between 2NO + 2H2 → N2 + 2H2O nitrogen and oxygen from the air C by the reaction between nitrogen 2NO + 2CO → N2 + 2CO2 compounds in petrol and oxygen from the air D by the reaction between nitrogen 2NO + 2H2 → N2 + 2H2O compounds in petrol and oxygen from the air

Question

Zinc is used to cover iron to prevent it from rusting. Why is zinc a suitable metal to use? A Iron is more reactive than zinc. B Iron atoms are bigger than zinc atoms. C Zinc is more reactive than iron. D Zinc atoms are bigger than iron atoms.

Question

Fertilisers are mixtures of different compounds used to increase the growth of crops. Which pair of substances contain the three essential elements for plant growth? A ammonium nitrate and calcium phosphate B ammonium nitrate and potassium chloride C ammonium phosphate and potassium chloride D potassium nitrate and calcium carbonate

Question

Which row describes the conditions used in the manufacture of sulfuric acid by the Contact process? catalyst pressure temperature A iron high high B iron low low C vanadium(V) oxide high low D vanadium(V) oxide low high

Question

Petroleum is an important raw material that is separated into useful products. Which terms describe petroleum and the method used to separate it? description separation method A compound cracking B compound fractional distillation C mixture cracking D mixture fractional distillation

Question

Which statements about propene are correct? 1 Propene contains only single bonds. 2 Propene decolourises bromine water. 3 Propene is obtained by cracking. 4 Propene is a hydrocarbon. A 1 and 4 B 2, 3 and 4 C 2 and 4 only D 4 only

Question

Which row describes the production of ethanol and its properties? can be made can be made is used as a is used as a from glucose from ethene fuel solvent A key B = yes C = no D

Question

Ethanoic acid is a typical carboxylic acid. Which statement about ethanoic acid is correct? A It can be oxidised to produce ethanol. B It is a proton acceptor. C It is fully dissociated in water. D It reacts with ethanol to produce ethyl ethanoate and water.

Question

Which structure represents the ester made from ethanoic acid and propanol? A B H H H O H H H O H H H H C C C O C C H H C C C O C C C H H H H H H H H H H C D H H O H H H O H H H C C C O C C H H C C O C C H H H H H H H H

Question

The structure of a polymer is shown. H O H O N C N C N C H O Which statements about the polymer are correct? 1 The polymer is nylon. 2 The polymer is formed by condensation polymerisation. 3 There are ester linkages between the monomers. A 1 and 2 B 2 and 3 C 2 only D 3 only 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.).