Chemistry 0620/23 October/November 2019: question paper and mark scheme

Question

Which two gases will diffuse at the same rate, at the same temperature? A carbon monoxide and carbon dioxide B carbon monoxide and nitrogen C chlorine and fluorine D nitrogen and oxygen

Question

A student is asked to measure the time taken for 0.4 g of magnesium carbonate to react completely with 25.0 cm3 of dilute hydrochloric acid. Which pieces of apparatus does the student need? A balance, stop-clock, pipette B balance, stop-clock, thermometer C balance, pipette, thermometer D stop-clock, pipette, thermometer

Question

A substance is separated using chromatography. The chromatogram is shown. solvent front P Q R baseline Which statement is not correct? A P has a higher Rf value than Q. B P, Q and R are all soluble in the solvent. C R is the most soluble substance. D The Rf value of P is less than 1.

Question

Which statement about an ionic compound is not correct? A It conducts electricity when dissolved in water. B It has a high melting point due to strong attractive forces between ions. C It has a regular lattice of oppositely charged ions in a ‘sea of electrons’. D The ionic bonds are formed between metallic and non-metallic elements.

Question

The numbers of protons, neutrons and electrons present in the atoms P, Q, R and S are shown. number number number atom of protons of neutrons of electrons P 4 5 4 Q 5 6 5 R 6 6 6 S 6 7 6 Which atoms are isotopes of the same element? A P and Q only B Q and R only C R and S only D P and S only

Question

Carbon has three isotopes, 12C, 13C and 14C. Why do all three isotopes have the same chemical properties? A They all have the same atomic mass. B They all have the same number of electrons in their outer shell. C They all have the same number of electron shells. D They all have the same number of nucleons.

Question

Silicon(IV) oxide is a covalently bonded compound. Which statements are correct? 1 Silicon atoms form four single bonds in silicon(IV) oxide. 2 Oxygen atoms form two double bonds in silicon(IV) oxide. 3 Silicon(IV) oxide has a high melting point. 4 Silicon(IV) oxide contains one silicon atom and four oxygen atoms. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 3 and 4 only

Question

Which statement describes the structure of copper? A It has a lattice of negative ions in a ‘sea of electrons’. B It has a lattice of negative ions in a ‘sea of protons’. C It has a lattice of positive ions in a ‘sea of electrons’. D It has a lattice of positive ions in a ‘sea of protons’.

Question

Magnesium carbonate decomposes on heating to form magnesium oxide and carbon dioxide as shown. MgCO3 → MgO + CO2 How much magnesium carbonate is needed to make 5.0 g of magnesium oxide? A 3.5 g B 4.0 g C 6.5 g D 10.5 g 10 90 g of glucose is dissolved in water. The glucose solution is fermented. C6H12O6 → 2CO2 + 2C2H5OH glucose, Mr = 180 ethanol, Mr = 46 After the fermentation finishes, 6.8 g of ethanol is obtained from the solution. What is the percentage yield of ethanol? A 7.4 B 7.6 C 14.8 D 29.6

Question

In the question paper above.

Question

The diagram shows a simple cell. voltmeter wire metal P copper dilute sulfuric acid Which metal P produces the smallest voltage? A calcium B iron C magnesium D zinc

Question

What are the ionic half-equations for the electrode reactions during the electrolysis of concentrated aqueous sodium chloride? anode cathode A Cl 2 + 2e– → 2Cl – H2 → 2H+ + 2e– B 2Cl – → Cl 2 + 2e– 2H+ + 2e– → H2 C H2 → 2H+ + 2e– Cl 2 + 2e– → 2Cl – D 2H+ + 2e– → H2 2Cl – → Cl 2 + 2e–

Question

An energy level diagram for a reaction is shown. energy progress of reaction Which statement and explanation about this reaction are correct? statement explanation A the reaction is endothermic the products have more energy than the reactants B the reaction is endothermic the products have less energy than the reactants C the reaction is exothermic the products have more energy than the reactants D the reaction is exothermic the products have less energy than the reactants

Question

Which gases are used to generate electricity in a fuel cell? A carbon dioxide and oxygen B hydrogen and methane C hydrogen and oxygen D methane and carbon dioxide

Question

A sequence of changes involving sulfur is shown. change 1 change 2 S(s) S(l) SO2(g) Which row describes the changes? change 1 change 2 A chemical chemical B chemical physical C physical chemical D physical physical

Question

Magnesium reacts with dilute hydrochloric acid. Which statement about the particles in the reaction is correct? A Increasing the concentration of dilute hydrochloric acid increases the collision rate but has no effect on the activation energy. B Increasing the concentration of dilute hydrochloric acid increases the collision rate and the activation energy. C Increasing the temperature of the reaction increases the activation energy. D Increasing the temperature of the reaction causes all collisions to lead to a reaction.

Question

Two molecules of nitrogen dioxide combine in a reversible reaction to form dinitrogen tetroxide. The forward reaction is exothermic. 2NO2(g) N2O4(g) Which changes in reaction conditions would both increase the amount of dinitrogen tetroxide at equilibrium? A decreasing the temperature and decreasing the pressure B decreasing the temperature and increasing the pressure C increasing the temperature and decreasing the pressure D increasing the temperature and increasing the pressure

Question

Chlorine displaces bromine from aqueous potassium bromide. The ionic equation for the reaction is shown. Cl 2 + 2Br– → 2Cl – + Br2 Which statement about this reaction is correct? A Bromide ions act as an oxidising agent. B Bromide ions are oxidised when electrons are lost. C Chlorine acts as a reducing agent. D Chlorine is reduced when electrons are lost.

Question

Which substance is a neutral oxide? A aluminium oxide B carbon monoxide C sulfur dioxide D zinc oxide

Question

Which statements about dilute sulfuric acid are correct? 1 It turns red litmus paper blue. 2 It reacts with magnesium(II) oxide to form magnesium(II) sulfate and water. 3 It reacts with magnesium to form magnesium(II) sulfate and carbon dioxide. 4 Its pH is below pH 7. A 1 and 2 only B 1 and 3 only C 2 and 4 only D 3 and 4 only

Question

A method used to make copper(II) sulfate crystals is shown. 1 Place dilute sulfuric acid in a beaker. 2 Warm the acid. 3 Add copper(II) oxide until it is in excess. 4 Filter the mixture. 5 Evaporate the filtrate until crystals start to form. 6 Leave the filtrate to cool. What are the purposes of step 3 and step 4? step 3 step 4 A to ensure all of the acid has reacted to obtain solid copper(II) sulfate B to ensure all of the acid has reacted to remove the excess of copper(II) oxide C to speed up the reaction to obtain solid copper(II) sulfate D to speed up the reaction to remove the excess of copper(II) oxide

Question

Lead(II) iodide is formed as a precipitate in the reaction shown. Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2NaNO3(aq) Which method is used to separate the lead(II) iodide from the mixture? A crystallisation B distillation C evaporation D filtration

Question

Which statement describes a gas which is in Group VIII of the Periodic Table? A A colourless gas that helps substances burn. B A pollutant gas present in car exhausts. C A gas that is less dense than air and makes a ‘pop’ sound with a lighted splint. D A gas that is used in lamps.

Question

Which pair of elements reacts together most violently? A chlorine and lithium B chlorine and potassium C iodine and lithium D iodine and potassium

Question

Iron reacts with dilute hydrochloric acid to form iron(II) chloride, FeCl 2. Iron reacts with chlorine to form iron(III) chloride, FeCl 3. Which property of transition elements is shown by this information? A Transition elements have high melting points. B Transition elements can act as catalysts. C Transition elements have variable oxidation states. D Transition elements have coloured compounds.

Question

Some properties of substance X are listed. ● It conducts electricity when molten. ● It has a high melting point. ● It burns in oxygen and the oxide dissolves in water to give a solution with pH 11. What is X? A a covalent compound B a macromolecule C a metal D an ionic compound

Question

Which statement about metals and their uses is correct? A Aluminium is used in the manufacture of aircraft because it has a high density. B Copper is used to make cooking utensils because it is a poor conductor of heat. C Mild steel is used to make car bodies because it is brittle and breaks easily. D Stainless steel is used to make cutlery because it is resistant to corrosion.

Question

Which word equation represents a reaction which occurs? A sodium oxide + carbon → sodium + carbon dioxide B sodium oxide + iron → sodium + iron(II) oxide C iron(II) oxide + copper → iron + copper(II) oxide D iron(III) oxide + carbon → iron + carbon dioxide

Question

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

Question

River water contains soluble impurities, insoluble impurities and bacteria. River water is made safe to drink by filtration and chlorination. Which statement is correct? A Filtration removes bacteria and insoluble impurities, and chlorination removes soluble impurities. B Filtration removes insoluble impurities, and chlorination kills the bacteria. C Filtration removes soluble and insoluble impurities, and chlorination kills the bacteria. D Filtration removes soluble impurities and bacteria, and chlorination removes insoluble impurities.

Question

How are oxygen and nitrogen separated from air? A chromatography B condensation and filtration C crystallisation D fractional distillation

Question

The apparatus shown is set up and left for a week. damp iron wool air water Which diagram shows the level of the water at the end of the week? A B C D

Question

The following processes are part of the carbon cycle. 1 photosynthesis 2 combustion 3 respiration Which processes decrease the amount of carbon dioxide in the atmosphere? A 1 only B 1 and 2 only C 1 and 3 only D 2 and 3 only

Question

Ammonium sulfate is used as a fertiliser. It is made from ammonia and sulfuric acid. Which words complete gaps 1, 2 and 3? The ……1…… is made by the ……2…… process in which ……3…… is used as a catalyst. 1 2 3 A ammonia Contact iron B ammonia Haber vanadium(V) oxide C sulfuric acid Contact vanadium(V) oxide D sulfuric acid Haber iron

Question

Which type of reaction occurs when lime is manufactured from limestone? A combustion B neutralisation C redox D thermal decomposition

Question

Which statement is correct? A Bitumen is used as a fuel for ships. B Coal, natural gas and oxygen are all fuels. C Hydrogen is the main constituent of natural gas. D Petroleum is separated into useful substances by fractional distillation.

Question

Which products are obtained by the cracking of an alkane? alkene hydrogen water A B C D

Question

Ethanol is made by fermentation of sugars and by the catalytic addition of steam to ethene. What are two advantages of making ethanol by the catalytic addition of steam to ethene rather than by fermentation of sugars? A faster reaction and renewable raw materials B purer product and faster reaction C renewable raw materials and continuous process D uses more energy and forms a purer product

Question

The diagram shows the structure of a monomer and of the polymer made from it. H H H H n C C C C H H H H n What are the monomer and polymer? monomer polymer A ethane poly(ethane) B ethane poly(ethene) C ethene poly(ethane) D ethene poly(ethene)

Question

Proteins and starch are both natural polymers. Both proteins and starch are hydrolysed by dilute acids. What are the products of hydrolysis of proteins and of starch? products of products of hydrolysis of proteins hydrolysis of starch A amines and carboxylic acids simple sugars B amines and carboxylic acids alcohols and carboxylic acids C amino acids simple sugars D amino acids alcohols and carboxylic acids 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 89–103 104 105 106 107 108 109 110 111 112 114 116 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.).