Chemistry 0620/23 May/June 2019: question paper and mark scheme

Question

Hydrogen chloride gas (Mr = 36.5) is released at P in the apparatus shown. The Universal Indicator paper turns red after 38 s. P Universal Indicator paper The experiment is repeated using sulfur dioxide (Mr = 64). What is the result for sulfur dioxide? Universal Indicator time for Universal Indicator turns to change colour / s A blue 26 B blue 51 C red 26 D red 51

Question

Which piece of apparatus is used to measure 24.8 cm3 of gas produced during a reaction? A beaker B conical flask C measuring cylinder D pipette

Question

Rf values are used to identify unknown substances using paper chromatography. Which statements about Rf values are correct? 1 Rf values are always less than 1.0. 2 Rf value = distance travelled by solvent ÷ distance travelled by unknown substance. 3 The higher the Rf value, the further the unknown substance travels. 4 Rf values are not affected by the solubility of the unknown substance. A 1 and 2 B 1 and 3 C 2 and 3 D 3 and 4

Question

The structure of an atom is shown. key = electron 7p n = neutron 8n p = proton Which element is the atom an isotope of? A nitrogen B oxygen C phosphorus D titanium

Question

Which row describes the formation of single covalent bonds in methane? A atoms share a pair of electrons both atoms gain a noble gas electronic structure B atoms share a pair of electrons both atoms have the same number of electrons in their outer shell C electrons are transferred from one both atoms gain a atom to another noble gas electronic structure D electrons are transferred from one both atoms have the same number atom to another of electrons in their outer shell

Question

Which statement describes the structure of an ionic compound? A It is a giant lattice of oppositely charged ions. B It is a giant lattice of positive ions in a ‘sea’ of electrons. C It is a giant molecule of oppositely charged ions. D It is a simple molecule of oppositely charged ions.

Question

When propane burns in air, carbon dioxide and water are formed. What is the chemical equation for this reaction? A C3H8 + 2O2 → CO2 + 2H2O B C3H8 + 3O2 → 3CO2 + H2O C C3H8 + 4O2 → 3CO2 + 4H2O D C3H8 + 5O2 → 3CO2 + 4H2O

Question

What is the concentration of a solution that contains 25.0 g NaOH in 500 cm3 of water? A 0.125 mol / dm3 B 0.800 mol / dm3 C 1.25 mol / dm3 D 3.20 mol / dm3

Question

An aqueous solution of copper(II) sulfate was electrolysed using copper electrodes. power supply copper – + copper cathode anode aqueous copper(II) sulfate Which equation for the reaction at the anode is correct? A Cu → Cu2+ + 2e– B Cu + 2e– → Cu2+ C Cu2+ → Cu + 2e– D Cu2+ + 2e– → Cu

Question

In the manufacture of aluminium by electrolysis, aluminium oxide is dissolved in molten cryolite. Why is cryolite used? A It lowers the melting point of the aluminium. B It makes the aluminium a better conductor. C It removes impurities from the aluminium. D The mixture has a lower melting point than pure aluminium oxide.

Question

Which statement about a fuel cell in a car is correct? A The fuel cell produces heat, which powers the car. B The fuel cell is supplied with hydrogen directly from the air. C The only emission from a fuel cell is nitrogen gas, which is non-polluting. D The fuel cell produces electricity, which powers an electric motor.

Question

Methane burns in oxygen to form carbon dioxide and water. CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) The bond energies are shown in the table. bond energy bond in kJ / mol C–H 410 C–O 360 C=O 805 O–H 460 O–O 146 O=O 496 What is the energy change for this reaction? A –818 kJ / mol B –102 kJ / mol C +102 kJ / mol D +818 kJ / mol

Question

Which change in reaction conditions increases both the collision rate and the proportion of molecules with sufficient energy to react? A addition of a catalyst B increasing the concentration of a reactant C increasing the surface area of a reactant D increasing the temperature of the reaction

Question

When blue-green crystals of nickel(II) sulfate are heated, water is produced and a yellow solid remains. When water is added to the yellow solid, the blue-green colour returns. Which process describes these changes? A combustion B corrosion C neutralisation D reversible reaction

Question

A reaction between nitrogen and oxygen is shown. The forward reaction is endothermic. N2(g) + O2(g) 2NO(g) Which change increases the equilibrium yield of nitrogen monoxide, NO? A decreasing the pressure B decreasing the temperature C increasing the pressure D increasing the temperature

Question

Which changes represent reduction? 1 Cl 2 + 2e– → 2Cl – 2 Mn(VII) → Mn(II) 3 sulfate(IV) → sulfate(VI) A 1 and 2 B 1 and 3 C 1 only D 2 only

Question

Which statement about carbon monoxide and aluminium oxide is correct? A Carbon monoxide and aluminium oxide are both amphoteric. B Carbon monoxide and aluminium oxide are both neutral. C Carbon monoxide is amphoteric but aluminium oxide is neutral. D Carbon monoxide is neutral but aluminium oxide is amphoteric.

Question

The positions of elements W, X, Y and Z in the Periodic Table are shown. W Y X Z Which elements form basic oxides? A W, X and Y B W and X only C Y only D Z only

Question

Solutions of acid R and acid S have the same concentration. The same volume of each acid at the same temperature is reacted with the same mass of magnesium ribbon. The volume of hydrogen produced is measured. The results are shown. volume of R hydrogen S 0 0 time Which statement about the reactions is correct? A Acid S reacts faster than acid R. B The final volume of hydrogen produced in each reaction is different. C Acid R is a stronger acid than acid S. D Acid S is a stronger acid than acid R.

Question

Part of the Periodic Table is shown. W X Y Z Which row describes W, X, Y and Z? metal non-metal A X W, Y and Z B X and Y W and Z C W and Z X and Y D W, Y and Z X

Question

Which statement about the properties of elements in Group I and in Group VII is correct? A Bromine displaces iodine from an aqueous solution of potassium iodide. B Chlorine, bromine and iodine are diatomic gases at room temperature. C Lithium, sodium and potassium are soft non-metals. D Lithium, sodium and potassium have an increasing number of electrons in their outer shells.

Question

Gas G has 10 electrons. Gas H has eight more electrons than gas G. Both gases are monoatomic. Which statement about G and H is correct? A Both gases are in the same group of the Periodic Table. B Both gases are in the same period of the Periodic Table. C Both gases are very reactive. D Gas G has a higher atomic mass than gas H.

Question

The diagrams show the structure of two substances used to make electrical conductors. X Y Which statement correctly describes X and Y? A X is a pure metal and Y is a compound. B X is a pure metal and Y is an alloy. C X is a solid and Y is a liquid. D X is harder and stronger than Y.

Question

Magnesium nitrate, magnesium hydroxide and magnesium carbonate all decompose when heated. Which statement about these decomposition reactions is correct? A Magnesium carbonate decomposes to release carbon dioxide and oxygen. B Magnesium hydroxide decomposes to release hydrogen and oxygen. C Magnesium hydroxide decomposes to release water vapour. D Magnesium nitrate decomposes to release oxygen only.

Question

Zinc is extracted from its ore, zinc blende, using two chemical reactions. 1 2ZnS + 3O2 → 2ZnO + 2SO2 2 2ZnO + C → 2Zn + CO2 Which substance is reduced in reactions 1 and 2? reaction 1 reaction 2 A O2 C B O2 ZnO C ZnS C D ZnS ZnO

Question

Four metals, zinc, M, copper and magnesium, are reacted with aqueous solutions of their nitrates. The results are shown. magnesium M copper zinc metal nitrate nitrate nitrate nitrate magnesium key zinc = reacts M = no reaction copper What is the order of reactivity of these four metals starting with the most reactive? A copper → zinc → M → magnesium B copper → M → zinc → magnesium C magnesium → M → zinc → copper D magnesium → zinc → M → copper

Question

Aluminium is used to make containers for storing food. Which property makes it suitable for this use? A conducts heat B low density C resists corrosion D shiny surface

Question

Water can be treated by filtration then chlorination. Which uses do not need water of this quality? 1 water for cooling in industry 2 water for washing clothes 3 water for drinking A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Catalytic converters in car exhausts change polluting gases into non-polluting gases. Which statements about oxides of nitrogen and car engines are correct? 1 The nitrogen in oxides of nitrogen comes from compounds in petrol. 2 The oxygen in oxides of nitrogen comes from the air in the car engine. 3 Catalytic converters convert oxides of nitrogen into nitrogen and other gases. A 1 and 2 B 2 and 3 C 2 only D 3 only

Question

The diagram shows an experiment to investigate how paint affects the rusting of iron. P Q iron painted iron air water What happens to the water level in tubes P and Q? tube P tube Q A falls rises B no change rises C rises falls D rises no change

Question

Which row about the carbon cycle is correct? process for removing process for returning carbon dioxide from carbon dioxide to the atmosphere the atmosphere A photosynthesis combustion of hydrocarbons B photosynthesis cracking of hydrocarbons C respiration combustion of hydrocarbons D respiration cracking of hydrocarbons

Question

Ammonia is manufactured in an exothermic reaction. N2(g) + 3H2(g) 2NH3(g) What is the effect of lowering the temperature on the rate of formation and equilibrium yield of ammonia? rate of formation equilibrium yield A decreases decreases B decreases increases C increases decreases D increases increases

Question

Which row shows the conditions used in the Contact process? temperature pressure catalyst / °C / atm A 25 2 iron B 25 200 iron C 450 2 vanadium(V) oxide D 450 200 vanadium(V) oxide

Question

The diagram represents a lime kiln used to heat limestone to a very high temperature. waste gases lime kiln limestone fuel in fuel in air in air in X What leaves the kiln at X? A calcium carbonate B calcium hydroxide C calcium oxide D calcium sulfate

Question

Which fuel could be gasoline? Is it obtained from petroleum? yes no Is it used as Is it used as fuel for cars? fuel for cars? yes no yes no A B C D

Question

Which statements about homologous series are correct? 1 All members have similar chemical properties. 2 All members have the same molecular mass. 3 Ethane and ethene are members of the same homologous series. 4 Ethane and propane are members of the same homologous series. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

Which type of reaction takes place when methane reacts with chlorine in the presence of ultraviolet light? A addition B cracking C polymerisation D substitution

Question

Which statement about aqueous ethanoic acid is correct? A It reacts with metal carbonates to form salts, hydrogen and water. B It reacts with metal oxides to form salts and oxygen. C It reacts with reactive metals to form salts and hydrogen. D It turns damp red litmus paper blue.

Question

The structure of ester W is shown. H O H C C H H O C H H Which row gives the names of ester W and the carboxylic acid and alcohol from which it is made? name of ester W carboxylic acid alcohol A ethyl methanoate ethanoic acid methanol B ethyl methanoate methanoic acid ethanol C methyl ethanoate ethanoic acid methanol D methyl ethanoate methanoic acid ethanol

Question

A section of a polymer is shown. H H O H H O H H O H H O O C C O C C C C O C C O C C C C H H H H H H H H How many different types of monomer units formed this section of polymer? A 1 B 2 C 3 D 4 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.).