Chemistry 0620/22 October/November 2024: question paper and mark scheme

Question

Oxygen melts at –219 °C and boils at –183 °C. At which temperature is oxygen a liquid? A –225 °C B –189 °C C –175 °C D 25 °C

Question

The pressure of a sample of gas is decreased. The temperature is kept constant. Which row describes the effects on the particles? movement collisions of particles between particles A slower occur less often B slower occur with more force C no change in speed occur less often D no change in speed occur with more force

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 electronic configuration. C They have different numbers of neutrons. D They have different mass numbers.

Question

Which pair of elements react to form a compound with a strong attraction between oppositely charged ions? A carbon and bromine B carbon and nitrogen C sodium and oxygen D sodium and potassium

Question

Four substances, P, Q, R and S, are described. ● P is diatomic. ● Q is a good conductor of electricity when solid and when molten. ● R is a silver solid with a very high melting point. ● S reacts with oxygen to form a brown gas. Which substances are metals? A P and Q B P and S C Q and R D R and S

Question

Which diagram shows the covalent bonding in a molecule of carbon dioxide? A O–C–O B O=C–O C O=C=O D O≡C≡O

Question

The bonding, structure and melting point of sodium chloride and sulfur dichloride are shown. compound bonding structure melting point / °C sodium chloride ionic giant lattice 801 sulfur dichloride covalent simple molecular –121 Why does sulfur dichloride have a lower melting point than sodium chloride? A The covalent bonds in sulfur dichloride are weaker than the attractive forces between molecules in sodium chloride. B The covalent bonds in sulfur dichloride are weaker than the ionic bonds in sodium chloride. C The attractive forces between molecules in sulfur dichloride are weaker than the attractive forces between molecules in sodium chloride. D The attractive forces between molecules in sulfur dichloride are weaker than the ionic bonds in sodium chloride.

Question

Diamond and graphite have giant covalent structures of carbon atoms. Which statement describes graphite? A It has a strong, rigid three-dimensional structure. B It has four strong covalent bonds between each carbon atom. C It has layers, which can slide over each other. D It has no delocalised electrons so does not conduct electricity.

Question

Which row explains the malleability and electrical conductivity of a solid metal? malleability electrical conductivity A Delocalised electrons can move Delocalised electrons can move freely through the structure. freely through the structure. B Delocalised electrons can move Positive ions can move freely freely through the structure. through the structure. C Rows of positive ions can Delocalised electrons can move slide over each other. freely through the structure. D Rows of positive ions can Positive ions can move freely slide over each other. through the structure.

Question

The equation for the decomposition of ammonium carbonate, (NH4)2CO3, is shown. (NH4)2CO3(s) → 2NH3(g) + CO2(g) + H2O(l) [Mr: (NH4)2CO3, 96] The total volume of gas produced is 360 cm3 at r.t.p. Which mass of ammonium carbonate, (NH4)2CO3, is decomposed? A 0.24 g B 0.48 g C 0.96 g D 1.44 g

Question

What is the empirical formula of a compound that contains 3.66 g of hydrogen, 37.8 g of phosphorus and 58.5 g of oxygen? A H6P2O6 B H4PO4 C H3PO3 D HPO

Question

Aqueous copper(II) sulfate is electrolysed using graphite electrodes. Which row identifies the product and observations at each electrode during the electrolysis? anode cathode product observation product observation A oxygen bubbles of gas copper electrode turns pink B copper electrode turns pink oxygen bubbles of gas C none electrode dissolves copper electrode turns pink D oxygen bubbles of gas and hydrogen bubbles of gas electrode dissolves

Question

Molten sodium chloride is electrolysed using inert electrodes. Which row shows the products formed at the cathode and anode? cathode anode A chlorine hydrogen B chlorine sodium C hydrogen chlorine D sodium chlorine

Question

The equation for the formation of ammonia is shown. N2 + 3H2 → 2NH3 The reaction pathway diagram for the reaction is shown. activation energy = +250 kJ / mol total energy N2 + 3H2 released energy = –342 kJ / mol enthalpy change 2NH3 progress of reaction What is the enthalpy change for the reaction? A –592 kJ / mol B –92 kJ / mol C +92 kJ / mol D +592 kJ / mol

Question

Sulfur dioxide is converted to sulfur trioxide in the Contact process. The conditions used are 450 °C and 200 kPa with a vanadium(V) oxide catalyst. Which row describes and explains the effect of changing conditions on the rate of reaction? change in conditions effect on rate explanation A no catalyst lower the activation energy is higher B higher pressure higher the particles have more kinetic energy C lower temperature lower the particles collide more frequently D lower pressure higher there are more particles per unit volume

Question

Hydrogen gas reacts with iodine gas to form hydrogen iodide gas in an equilibrium reaction. H2(g) + I2(g) 2HI(g) ∆H = +26.5 kJ / mol Which changes increase the yield of HI at equilibrium? 1 adding a catalyst 2 adding more hydrogen gas 3 increasing the pressure 4 increasing the temperature A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

Question

The equation for the reaction of carbon with carbon dioxide is shown. C + CO2 → 2CO Which row identifies the carbon atom that is reduced and its change in oxidation number? change in atom that is reduced oxidation number A carbon in CO2 +2 → +4 B carbon in CO2 +4 → +2 C elemental carbon, C 0 → +2 D elemental carbon, C +2 → 0

Question

Aqueous iron(II) sulfate is added to acidified potassium manganate(VII). The purple colour of the potassium manganate(VII) disappears. Aqueous potassium iodide is added to acidified potassium dichromate(VI). A dark brown solution forms. Which row identifies the role of the iron(II) sulfate and the potassium dichromate(VI) in these reactions? iron(II) sulfate potassium dichromate(VI) A oxidising agent oxidising agent B oxidising agent reducing agent C reducing agent reducing agent D reducing agent oxidising agent

Question

Which row shows the difference between a weak acid and a strong acid? weak acid strong acid A fully dissociated partially dissociated B concentrated dilute C dilute concentrated D partially dissociated fully dissociated

Question

Which substance turns methyl orange red? A aqueous ammonia B dilute hydrochloric acid C aqueous sodium hydroxide D distilled water

Question

Which row describes zinc oxide and calcium oxide? zinc oxide calcium oxide A basic acidic B acidic basic C amphoteric acidic D amphoteric basic

Question

Which row shows the properties of a transition element? colour electrical catalyst of oxide conductivity A yes red good B yes green poor C no yellow good D no white poor

Question

Fluorine is the element at the top of Group VII of the Periodic Table. Which statement describes fluorine? A It is inert. B It is monatomic. C It is non-metallic. D It is a solid at room temperature.

Question

When aluminium is placed in dilute hydrochloric acid, there is no reaction. When zinc is placed in dilute hydrochloric acid, bubbles of gas are immediately given off. Which statement correctly explains these observations? A Aluminium is coated with a layer of aluminium oxide. B Aluminium is more reactive than hydrogen. C Aluminium is less reactive than zinc. D Zinc is less reactive than hydrogen.

Question

Which statements about the use of sacrificial protection to prevent iron from rusting are correct? 1 A more reactive metal than iron is used as a sacrificial protector because it undergoes reduction before iron. 2 Zinc is used as a sacrificial protector because it gains electrons more readily than iron. 3 Copper is not used as a sacrificial protector because it is less reactive than iron. 4 Magnesium is used as a sacrificial protector because it loses electrons more readily than iron. A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4

Question

Aluminium is extracted from its ore by electrolysis. What is the role of cryolite in this process? A to lower the operating temperature B to lower the boiling point of bauxite C to raise the melting point of bauxite D to act as a catalyst

Question

Which row identifies two greenhouse gases and three processes by which they contribute to global warming? two greenhouse gases three processes A carbon dioxide and methane absorption, creation and reflection of thermal energy B carbon dioxide and oxygen absorption, creation and reflection of thermal energy C carbon dioxide and methane absorption, emission and reflection of thermal energy D methane and oxygen absorption, emission and reflection of thermal energy

Question

Which mixture contains all of the elements in a typical NPK fertiliser? A ammonium nitrate and calcium phosphate B ammonium phosphate and potassium chloride C potassium nitrate and ammonium chloride D potassium carbonate and ammonium nitrate

Question

Bromine reacts with but-2-ene. What is the displayed formula of the product of this reaction? A B H Br H H H H H H H C C C C H H C C C C H H Br H H Br Br H H C D H H H H H H H H H C C C C H H C C C C H H Br Br H Br H H Br

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 statement explains why ethanoic acid is saturated? A The molecule dissociates completely in water. B There is a carbon–oxygen double bond in the molecule. C The carbon–carbon bond in the molecule is a single bond. D All the carbon–hydrogen bonds in the molecule are single bonds.

Question

Which statement about compounds in the same homologous series is correct? A They have the same chemical properties because they have the same number of carbon atoms. B They have the same physical properties because they have the same number of carbon atoms. C They have different chemical properties because they have different numbers of carbon atoms. D They have different physical properties because they have different numbers of carbon atoms.

Question

Which row shows the properties of methane? gives a positive soluble state at room test with in water temperature aqueous bromine A no gas no B no gas yes C yes liquid no D yes liquid yes

Question

The table shows two methods used to make ethanol. conditions source type of method temperature pressure of raw process catalyst / °C / atm material fermentation batch 35 1 yeast sugar cane adding steam continuous 300 60 acid petroleum to ethene Which statement gives an advantage of preparing ethanol by fermentation rather than by adding steam to ethene? A Fermentation takes several days to complete. B Little energy is used in the fermentation process. C The fermentation of glucose from sugar cane produces pure ethanol. D Fermentation uses a non-renewable raw material.

Question

Which equation represents an addition reaction? A CH3CHO + HCN → CH3CH(OH)CN B C6H6 + Br2 → C6H5Br + HBr C NH4Br → NH3 + HBr D C14H30 → C2H4 + C8H18 + C4H8

Question

The structure of part of a polymer is shown. H H H H O H H H H C N C C C C O C N C C C H O H H H O H H How many amide and ester linkages are included in the structure shown? amide ester linkages linkages A 1 0 B 1 1 C 2 1 D 2 2

Question

Which structure represents part of a protein? A B H O H O O O N C N C C C O O C D H H O O H O H O N N C C N C O N C

Question

Which piece of apparatus can only measure a single fixed volume? A a 250 cm3 beaker B a 50 cm3 burette C a 100 cm3 measuring cylinder D a 25 cm3 volumetric pipette

Question

Pure solid copper(II) nitrate can be obtained from a mixture of copper(II) nitrate and copper powder. Three stages in the method are listed. X add water and stir Y crystallise Z filter After the three stages, the copper(II) nitrate is washed and dried. What is the correct order of stages X, Y and Z to obtain pure solid copper(II) nitrate from the mixture? A X→Y→Z B X→Z→Y C Y→X→Z D Z→X→Y

Question

Which row describes a test and the observation for aqueous sulfate ions? test observation A add dilute nitric acid a gas is produced which turns limewater cloudy B add dilute nitric acid and white precipitate forms aqueous barium nitrate C add dilute nitric acid and solution decolourises aqueous potassium manganate(VII) D add dilute nitric acid white precipitate forms and aqueous silver nitrate 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.).