Chemistry 0620/12 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

Which statement explains why water is a compound? A The hydrogen and oxygen atoms in a molecule of water can only be separated by chemical means. B The hydrogen and oxygen atoms in a molecule of water can be separated using physical means. C The number of hydrogen and oxygen atoms in a molecule of water is variable. D Water has the same chemical properties as both hydrogen and oxygen.

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

Which row describes properties of lithium fluoride? electrical conductivity electrical conductivity melting point when solid when molten A does not conduct conducts high B does not conduct does not conduct low C conducts conducts high D conducts does not conduct low

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 substance has a giant covalent structure? A ethanol B graphite C methane D sodium chloride

Question

Sodium burns in oxygen to form sodium oxide. What is the balanced equation for the reaction? A 4Na + 2O → 2Na2O B 4Na + O2 → 2Na2O C 2Na2 + O2 → 2Na2O D 2Na2 + 2O → 2Na2O

Question

What is the relative formula mass of Mg(OH)2? A 21 B 30 C 42 D 58

Question

Dilute sulfuric acid is electrolysed using inert electrodes. The apparatus is set up as shown. dilute sulfuric acid graphite graphite cathode anode – + 30 cm3 of a gas is collected at the cathode. A different gas is collected at the anode. Which row is correct? volume of gas gas at gas at collected at anode cathode anode / cm3 A hydrogen oxygen 15 B hydrogen oxygen 30 C oxygen hydrogen 15 D oxygen hydrogen 30

Question

Four statements about hydrogen fuel cells are listed. 1 The fuel cell converts chemical energy into electrical energy. 2 In the fuel cell, hydrogen combines with oxygen. 3 Carbon dioxide and water are produced in the fuel cell. 4 The hydrogen fuel is extracted from the air. Which statements are correct? A 1 and 2 B 1 and 4 C 2 and 3 D 2 and 4 11 5 g of four different fuels are set alight and placed under a beaker containing 50 cm3 of water. The temperature of the water is taken at the start and after five minutes. Which fuel releases the most energy? temperature temperature at start after five minutes / °C / °C A 15 23 B 21 31 C 28 47 D 30 48

Question

In the question paper above.

Question

Which changes increase the rate of reaction? 1 increasing the concentration of the reactants 2 increasing the particle size of a solid reactant 3 increasing the temperature A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

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 between iron(III) oxide and carbon is shown. 2Fe2O3 + 3C → 4Fe + 3CO2 Which type of reaction does iron(III) oxide undergo? A reduction B precipitation C oxidation D combustion

Question

Copper(II) chloride is made when copper(II) carbonate reacts with dilute hydrochloric acid. What are the other products in this reaction? A water and carbon dioxide B carbon dioxide only C water and hydrogen D hydrogen only

Question

Rubidium is in Group I and strontium is in Group II of the Periodic Table. Which row describes the nature of rubidium oxide, Rb2O, and strontium oxide, SrO? Rb2O SrO A acidic acidic B acidic basic C basic acidic D basic basic

Question

Magnesium sulfate is a soluble solid which is formed when insoluble magnesium oxide reacts with dilute sulfuric acid. Which method is used to prepare solid magnesium sulfate? A Excess sulfuric acid is reacted with magnesium oxide. The mixture is evaporated to dryness. B Excess sulfuric acid is reacted with magnesium oxide. The precipitate is filtered, washed and dried. C Sulfuric acid is reacted with excess magnesium oxide. The mixture is filtered and the filtrate is evaporated to dryness. D Sulfuric acid is reacted with excess magnesium oxide. The precipitate is filtered, washed and dried.

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

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

Aqueous bromine is added to aqueous sodium iodide. bromine + sodium iodide → ……1…… + ……2…… What are the products of this reaction? 1 2 A iodide sodium bromide B iodide sodium bromine C iodine sodium bromide D iodine sodium bromine

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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

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Which row describes the properties of argon? property 1 property 2 A inert diatomic B inert monatomic C reactive diatomic D reactive monatomic

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

Which reaction in the blast furnace releases heat energy? A C + O2 → CO2 B CaCO3 → CaO + CO2 C CO2 + C → 2CO D Fe2O3 + 3CO → 2Fe + 3CO2

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

Urea, CO(NH2)2, is used as a fertiliser. Which element that plants need for improved plant growth is provided by urea? A carbon B hydrogen C nitrogen D oxygen

Question

The percentage composition of gases on Neptune is shown. percentage gas composition / % hydrogen 80 helium 18 methane 1.5 other gases 0.5 Which statement about the atmospheres on Neptune and on the Earth is correct? A There is more helium on Neptune than oxygen on the Earth. B There is less methane on Neptune than carbon dioxide on the Earth. C There is less hydrogen on the Earth than on Neptune. D There is more helium on the Earth than on Neptune.

Question

Which row shows the general formula for alkenes and for alcohols? alkenes alcohols A CnH2n CnH2n+1COOH B CnH2n CnH2n+1OH C CnH2n+2 CnH2n+1COOH D CnH2n+2 CnH2n+1OH

Question

A molecule has the formula C2H5Cl. What is its chemical name? A chloroethane B chloroethanol C chloroethene D chloromethanol

Question

Which compound rapidly decolourises aqueous bromine? A ethane B ethanoic acid C ethanol D ethene

Question

Compound Z has the molecular formula C2H6O. Which statement about compound Z is correct? A Z is unsaturated. B Z is a carboxylic acid. C Z is formed by the reaction of ethane with steam. D Z is used as a fuel.

Question

What is the formula of the salt formed when aqueous ethanoic acid reacts with calcium carbonate? A Ca(CH3COOH)2 B Ca(CH3COO)2 C Ca2CH3COOH D Ca2CH3COO

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

Chromatography is carried out on mixture Y and dyes E, F, G and H. The chromatogram is shown. solvent front baseline Y E F G H Which dyes are present in mixture Y? A E and G B E and H C F and G D F and H

Question

A fractionating column is used to separate the hydrocarbon fractions in petroleum by fractional distillation. Which row describes the properties of the fractions that condense at the top of the fractionating column? size of molecule boiling point A large high B large low C small high D small low

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.).