Chemistry 0620/22 October/November 2019: question paper and mark scheme

Question

The rate of diffusion of a gas depends on its molecular mass and the temperature. Which combination of molecular mass and temperature gives the slowest rate of diffusion? molecular mass temperature A high high B high low C low high D low low

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

Substance Q was investigated using chromatography. The chromatogram is shown. The diagram is not drawn to scale. solvent front Q 129 mm 114 mm 83 mm baseline 13 mm Q What is the Rf value of Q? A 0.60 B 0.64 C 0.69 D 0.72

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

What is the total number of electrons in one molecule of ammonia, NH3? A 6 B 8 C 10 D 11

Question

Rubidium has two isotopes, 85 87 37 Rb and 37 Rb . Which statement explains why both isotopes have the same chemical properties? A They have the same number of protons. B They have the same number of outer shell electrons. C They have different numbers of neutrons. D They have different mass numbers.

Question

Which statement about the structure and properties of silicon(IV) oxide is not correct? A It has a giant structure similar to that of diamond. B It has a high melting point due to the strong attractive force between molecules. C There are strong covalent bonds between silicon and oxygen. D There are no free electrons, so silicon(IV) oxide does not conduct electricity.

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

Phosphorus reacts with oxygen to form phosphorus(III) oxide as shown. 4P(s) + 3O2(g) → 2P2O3(s) Which mass of phosphorus(III) oxide is produced from 6.2 g of phosphorus? A 1.1 g B 5.5 g C 11.0 g D 22.0 g

Question

Calcium carbonate is heated. Calcium oxide and carbon dioxide gas are formed. The equation for the reaction is shown. CaCO3 → CaO + CO2 225 kg of calcium carbonate is heated until there is no further change in mass. The yield of calcium oxide is 85 kg. What is the percentage yield? A 37.8% B 47.2% C 67.5% D 85.0%

Question

The diagram shows a simple cell. voltmeter wire metal P metal Q dilute sulfuric acid Which pair of metals produces the largest voltage? metal P metal Q A magnesium iron B magnesium copper C zinc iron D zinc copper

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

The temperature of the water in two beakers, X and Y, is measured as 21.5 °C. 5 g of sodium chloride is dissolved in the water in beaker X. The temperature changes to 18.0 °C. 5 g of calcium oxide is dissolved in the water in beaker Y. The temperature changes to 29.4 °C. Which types of process are occurring in beakers X and Y? X Y A endothermic endothermic B endothermic exothermic C exothermic endothermic D exothermic exothermic

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

Which row identifies a chemical and a physical change? chemical change physical change A boiling ethanol burning ethanol B burning ethanol evaporating ethanol C dissolving ethanol in water burning ethanol D evaporating ethanol dissolving ethanol in water

Question

A sample of dilute nitric acid is added to lumps of limestone in a conical flask. The conical flask is placed on a balance and the loss in mass is measured. A second sample of nitric acid of a different concentration is separately tested. All other conditions are kept the same. The loss in mass in 1 minute at each concentration of nitric acid is shown. concentration loss in mass in in mol / dm3 1 minute / g 0.5 0.15 1.0 0.25 Which row describes and explains the results obtained using 1.0 mol / dm3 nitric acid compared with 0.5 mol / dm3 nitric acid? description explanation A decrease in reaction rate decrease in particle collision energy B decrease in reaction rate increase in particle collision rate C increase in reaction rate increase in particle collision rate D increase in reaction rate increase in particle collision rate and collision energy

Question

When carbon monoxide reacts with hydrogen, methanol is formed. CO(g) + 2H2(g) CH3OH(g) The forward reaction is exothermic. Which statements are correct? 1 There are more moles of gas on the left-hand side of the reaction. 2 Increasing the temperature increases the amount of methanol at equilibrium. 3 Increasing the pressure increases the amount of methanol at equilibrium. 4 Increasing the initial amount of hydrogen decreases the amount of methanol at equilibrium. A 1 and 2 only B 1 and 3 only C 2 and 4 only D 3 and 4 only

Question

In the blast furnace, iron is formed when iron(III) oxide reacts with carbon monoxide in a redox reaction. Fe2O3 + 3CO → 2Fe + 3CO2 Which substance is the oxidising agent and which substance is the reducing agent? oxidising agent reducing agent A CO Fe2O3 B CO2 Fe C Fe CO2 D Fe2O3 CO

Question

Which oxide is classified as an amphoteric oxide? A aluminium oxide B calcium oxide C copper(II) oxide D nitrogen oxide

Question

Which statement describes the properties of hydrochloric acid? A Carbon dioxide is produced when limestone reacts with hydrochloric acid. B Hydrogen is produced when sodium hydroxide reacts with hydrochloric acid. C Methyl orange turns yellow in strong hydrochloric acid. D Red litmus paper turns blue when dipped into hydrochloric acid.

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) 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

Helium is a noble gas. Which statement about helium is correct? A It has eight electrons in its outer shell. B It is a diatomic gas. C It is reactive. D It is used for filling balloons.

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(II) ions can be oxidised to iron(III) ions by hydrogen peroxide. Which statement explains why iron is a transition element? A Iron is a transition element because it can be oxidised. B Iron is a transition element because it has variable oxidation states. C Iron is a transition element because it takes part in redox reactions. D Iron is a transition element because it reacts with chlorine.

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 row describes the uses of aluminium, copper and mild steel? aluminium copper mild steel A aircraft bodies electrical wiring car bodies B car bodies cooking utensils electrical wiring C electrical wiring aircraft bodies food containers D food containers aircraft bodies cooking utensils

Question

The properties of four metals are listed. ● Metal W does not react with dilute hydrochloric acid. ● Metal X reacts with dilute hydrochloric acid. ● Metal Y displaces metal X from an aqueous solution of its ions. ● Metal Z reacts with water and dilute hydrochloric acid. What is the order of reactivity of the metals? most least reactive reactive A W X Y Z B W Y X Z C Z X Y W D Z Y X W

Question

Which statement about the extraction of aluminium from aluminium oxide is correct? A Aluminium is formed at the positive electrode during electrolysis. B Pure aluminium oxide is dissolved in molten cryolite. C Pure aluminium oxide is electrolysed using aluminium as the positive electrode. D Pure aluminium oxide is heated with carbon to form carbon dioxide and aluminium.

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

Which process is used to separate nitrogen and oxygen from air? A chromatography B evaporation C filtration 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 diagram represents an outline of the carbon cycle. carbon dioxide photosynthesis in the atmosphere Y respiration X plants animals power stations death and excretion organic waste fossil fuels Which processes are X and Y? X Y A combustion respiration B decomposition respiration C photosynthesis combustion D respiration combustion

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 statement about limestone and lime is correct? A Limestone combines with water to produce slaked lime. B Lime is obtained from limestone by oxidation. C Lime is used in the desulfurisation of flue gases. D Lime is used in the treatment of alkaline soil.

Question

Some fractions obtained from petroleum are listed. position collected fraction use in the fractionating column 1 gasoline waxes and polishes below refinery gas 2 bitumen making roads above kerosene 3 kerosene jet fuel below gasoline 4 refinery gas heating and cooking above gasoline Which rows are correct? A 1, 3 and 4 B 2, 3 and 4 C 3 and 4 only D 4 only

Question

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

Question

Ethanol is produced by fermentation or by the reaction of ethene with steam. Which row is correct? by fermentation from ethene A uses a temperature of 100 °C uses a temperature of 350 °C B needs yeast as a catalyst does not need a catalyst C very slow reaction very fast reaction D high yield of ethanol low yield of ethanol

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

The structure of a naturally occurring polymer, X, is shown. H O H O N C N C N C H O What is X? A an amino acid B a carbohydrate C a protein D a sugar 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.).