Chemistry 2022 · Oct/Nov · Paper 12

Why is the first ionisation energy of phosphorus greater than the first ionisation energy of silicon? A A phosphorus atom has one more proton in its nucleus. B The atomic radius of a phosphorus atom is greater. C The outer electron in a phosphorus atom is more shielded. D The outer electron in a phosphorus atom is paired.

Sodium peroxide, Na 2O2, is used to absorb carbon dioxide from the atmosphere and release oxygen in closed environments such as space capsules and submarines. 2Na Which mass of sodium peroxide would be required to remove 2.4 of carbon dioxide from the atmosphere at room temperature and pressure? A 2.4 g B 3.9 g C 7.8 g D 15.6 g

In which species are the numbers of protons, neutrons and electrons all different?S D

Calcium oxide and magnesium sulfide each react with acid. CaO(s) + 2H

+ H2O(l) MgS(s) + 2H

+ H2S

A mixture of these two compounds, X, reacts with exactly 0.125 mol of dilute hydrochloric acid. The amount of hydrogen sulfide formed is 0.0250 mol. What was the mass of calcium oxide in mixture X? A 1.4 g B 2.1 g C 2.8 g D 4.2 g 5 Two moles of VO + ions react with one mole of zinc atoms in the presence of dilute acid. The products include Zn ions and an ion, Y. Ion Y contains vanadium. Only zinc and vanadium change oxidation state in the reaction. What is ion Y? A VO - B VO C VO D VO 2

The compound potassium bismuthate(V), KBiO3, is a powerful oxidising agent. What is the significance of the ( V) in potassium bismuthate(V)? A It is the oxidation number of the bismuth atom. B It is the charge of the bismuthate ion. C It is the oxidation number of the bismuthate ion. D It is the sum of the charges of the two ions present.

Hydrogen peroxide decomposes slowly at 20 2O2 2H2O + O2 equilibrium constant = K c The reaction is faster when a catalyst is present. Which statement is correct? A The catalyst alters the Boltzmann distribution so that the reactant molecules have more energy. B The catalyst has no effect on the value of K C The catalyst increases the value of K D The catalyst provides a different reaction mechanism with a higher activation energy.

A dimer, Q, is stable when solid but a dynamic equilibrium is set up in solution. Q(aq) 2R(aq) A solution of Q has an initial concentration of 0.50 mol dm . When equilibrium has been reached, [Q(aq)] has fallen to 0.25 mol dm The changes in [Q(aq)] and [R(aq)] are plotted against time until equilibrium is reached. The value of K c is then calculated. Which graph and value for K c are correct? A 1 / mol dm graph 0.5 0.4 0.3 0.2 0.1 0 time B 0.25 0.5 0.4 0.3 0.2 0.1 0 timeC 1 0.5 0.4 0.3 0.2 0.1 0 timeD 2 0.5 0.4 0.3 0.2 0.1 0 time concentration mol dm concentration mol dm concentration mol dm concentration mol dm

The reaction pathway for the forward reaction of a reversible reaction is shown. energy kJ mol progress of reaction Which statement is correct? A The activation energy of the reverse reaction is +80 kJ mol B The enthalpy change for the forward reaction is +30 kJ mol C The enthalpy change for the forward reaction is +50 kJ mol D The enthalpy change for the reverse reaction is +30 kJ mol

The enthalpy changes for the possible reactions W, X, Y and Z are given. W NaOH(aq) + HCl = -56 kJ mol = +56 kJ mol = +11 kJ mol = -11 kJ mol Which statement about the activation energies of these reactions is correct? A X is greater than W; Z is greater than Y. B X is greater than W; Y is greater than Z. C W is greater than X; Z is greater than Y. D W is greater than X; Y is greater than Z.

The Haber process is carried out with a nitrogen partial pressure of 50 kPa, a hydrogen partial pressure of 150 2

+ 3H2

If all other conditions are kept the same, which change will result in a raised activation energy? A Both the nitrogen and hydrogen partial pressures are changed to 100 kPa. B The iron is removed. C The nitrogen partial pressure is increased to 150 kPa. D The temperature is increased to 500

The compound (CH 3)3NAl Cl 3 has a simple molecular structure. Which statement about (CH 3)3NAl Cl 3 is correct? A (CH 3)3NAl Cl 3 molecules attract each other by hydrogen bonds. B The Al atom in (CH 3)3NAl Cl 3 has an incomplete valence shell of electrons. C The bonds around the Al atom are planar. D The molecules contain coordinate bonding.

VSEPR theory should be used in answering this question. The dot-and-cross diagram for an ozone, O 3, molecule is shown. What is the predicted bond angle in this molecule?

Each of the substances shown is gaseous. Which substance is most likely to show ideal behaviour in the conditions shown? substance temperature pressure / Pa

Which graph represents the variation of pressure p and volume V of a sample of an ideal gas at constant temperature?

Use relevant enthalpy changes from the tables to answer this question. / kJ mol bond bond enthalpy kJ mol H-H 436 C-C 350 C=C 610 C=O 805 Which value can be calculated for the enthalpy change for the following reaction? 2H6

A -2822 kJ mol B -2122 kJ mol C -1998 kJ mol D -1772 kJ mol

Element X requires strong heating to react with oxygen. Element X reacts with chlorine to give a covalently-bonded chloride. What could be the identity of element X? A magnesium B phosphorus C sodium D silicon

The melting points of the Period 3 elements sodium to aluminium are shown in the table. element Na Mg Al melting point / K 371 923 932 Which factor explains the increase in melting points from sodium to aluminium? A the change in first ionisation energy from sodium to aluminium B the increase in electronegativity from sodium to aluminium C the increase in the A r of the elements from sodium to aluminium D the increase in the number of outer electrons in each atom from sodium to aluminium

The nitrates of beryllium, calcium, magnesium and strontium all decompose in the same way when heated. When 2.00 g of one of these anhydrous nitrates is decomposed, 1.32 g of gas is produced. What is the nitrate? A beryllium nitrate B calcium nitrate C magnesium nitrate D strontium nitrate

In the diagram, each test-tube W, X, Y and Z contains 25 cm of a 0.1 mol dm solution of a salt. 25 cm BaCl

25 cm MgCl

25 cm BaCl

25 cm MgCl

To test-tubes W and X, 25 of 0.1 mol dm NaOH(aq) is added. To test-tubes Y and Z, 25 of 0.1 mol dm H2SO4(aq) is added. In which of test-tubes W and X does the liquid have the higher pH and which of test-tubes Y and Z has the greater mass of precipitate? higher pH greater mass of precipitate A W Y B W Z C X Y D X Z

What is the oxidation state of the chlorine-containing species that kills bacteria in drinking water? A -1 B +1 C +3 D +5

Compound Q is a white crystalline solid which dissolves easily in water. When concentrated sulfuric acid is added to a dry sample of Q, steamy white fumes are formed. When these white fumes are passed into aqueous silver nitrate solution, a white precipitate forms. This precipitate is soluble in dilute ammonia solution. What is compound Q? A AgCl B NaBr C NaCl D PbBr

R is a solid. R fizzes when hydrochloric acid is added. R reacts with hot aqueous sodium hydroxide, giving off a gas which turns red litmus blue. What is the formula of R? A NH 4CO3 B (NH 4)2CO3 C (NH 4)2HCO3 D (NH 4)2SO4

Photochemical smog is a type of air pollution produced in urban areas by the effect of sunlight on substances released from vehicle exhausts. Which mixture of primary pollutants leads to the formation of photochemical smog? A carbon dioxide and water vapour B carbon monoxide and unburnt hydrocarbons C nitrogen oxide and unburnt hydrocarbons D sulfur dioxide and water vapour

T is an element in Period 3. The first ionisation energy of T is lower than that of the element with one less proton. The oxide of T does not react with water. What is the identity of T? A aluminium B silicon C sodium D sulfur

The structure of tartaric acid is shown. tartaric acid Which statements about tartaric acid are correct? 1 A molecule of tartaric acid has more than one chiral centre. 2 The molecular formula of tartaric acid is C 4H4O6. 3 One molecule of tartaric acid produces four hydrogen ions in aqueous solution. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only

A carboxylic acid, P, has no chain isomers. It reacts with an alcohol, Q, that has only one positional isomer. What could be the ester formed from a reaction between P and Q? A butyl propanoate B ethyl butanoate C pentyl ethanoate D propyl pentanoate

Which pair includes a hydrocarbon without a chiral centre? A CH 3CH2CH2CH(CH3)CH2CH3 CH 3CH(CH3)CH(CH3)CH2CH3 B CH 3CH2CH2CH(CH2CH3)CH3 CH 3CH2CH2CH(CH3)CH2CH3 C CH 3CH2CH2CH(CH3)CH2CH3 CH 3CH2CH(CH3)CH(CH3)2 D CH 3CH(CH2CH3)CH(CH3)CH3 CH 3CH(CH3)CH2CH(CH3)2

What is the major product formed when compound R is warmed with an excess of HBr? Br OH Br Br

cis-but-2-ene reacts with cold dilute acidified potassium manganate( VII) solution to give product X. cis-but-2-ene reacts with hot concentrated acidified potassium manganate( VII) solution to give product Y. Which row describing the reactions of X and Y is correct? when sodium metal is added to separate samples of X and Y when sodium hydroxide solution is added to separate samples of X and Y A both X and Y will react neither X nor Y will react B both X and Y will react only one of X and Y will react C only one of X and Y will react neither X nor Y will react D only one of X and Y will react only one of X and Y will react

For which reaction will the major organic product have the lowest relative molecular mass? A Bromoethane is heated under reflux with an aqueous solution of sodium hydroxide. B Bromoethane is heated under reflux with a solution of sodium cyanide in ethanol. C 2-bromopropane is heated under reflux with an aqueous solution of sodium hydroxide. D 2-bromopropane is heated under reflux with concentrated ethanolic sodium hydroxide. 32 C 4H9Cl reacts with warm dilute aqueous sodium hydroxide solution. Which isomer of C 4H9Cl will form the most stable cation intermediate? A 1-chlorobutane B 2-chlorobutane C 1-chloro-2-methylpropane D 2-chloro-2-methylpropane

1.0 mol of an organic compound, J, requires 6.0 mol of oxygen for complete combustion. 1.0 mol of J reacts with sodium, producing 0.50 mol of a gas that gives a 'pop' with a lighted splint. J reacts with an excess of hot acidified potassium manganate( VII) to produce an organic compound which gives an orange-red precipitate with 2,4-DNPH reagent. Which compound is J? A but-1-ene B butan-2-ol C propan-2-ol D 2-methylpropan-2-ol

Structural isomerism and stereoisomerism should be considered when answering this question. 3-methylhexan-3-ol reacts with hot concentrated sulfuric acid to form several isomeric compounds with the molecular formula C 7H14. 3-methylhexan-3-ol How many isomeric compounds could be formed in this reaction? A 3 B 4 C 5 D 6

The table shows a student's predictions for the reactions of three compounds. compound alkaline 2(aq) Fehling's reagent Tollens' reagent 3 3 3key = reaction occurs 7 = no reaction 3 7 7 7 7 7 Which rows show the correct predictions? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

Which mechanism describes the reaction of aldehydes and ketones with HCN + NaCN? A electrophilic addition B electrophilic substitution C nucleophilic addition D nucleophilic substitution

Propyl propanoate can be synthesised in three steps using propanenitrile as the only organic starting material. In step 1, the nitrile is converted into compound X. In step 2, compound X is converted into compound Y. In step 3, compound Y is reacted with more of compound X to give propyl propanoate. step 1 step 2 step 3 3CH2CN CH3CH2CO2CH2CH2CH3 Which reagents are suitable for carrying out step 1 and step 2? step 1 step 2 A HCl (aq) conc. H 2SO4 B HCl (aq) LiA l H4 C NaOH(aq) conc. H 2SO4 D NaOH(aq) NaBH 4 38 The ester CH 3CH2CO2CH3 is hydrolysed by boiling with aqueous sodium hydroxide. Which compound is one of the products? A ethanol B propan-1-ol C sodium methanoate D sodium propanoate

Compound V polymerises to form polymer W. A section of polymer W is shown. polymerisation polymer W ClClCl ClCl What is the correct name of compound V? A 1,1,2-trichlorobutene B 1,1,2-trichloroethene C 1,1,2-trichloropropene D 1,1,2-trichloro-2-methylethene

A molecule of an organic compound, P, contains three carbon atoms and shows a strong absorption at 1720 in its infrared spectrum. P is reacted with an excess of hot acidified potassium dichromate( VI) forming organic product Q. Q shows a strong absorption at 1700 and a strong, broad absorption centred at 2800 cm its infrared spectrum. bond functional group containing the bond characteristic infrared absorption range (in wavenumbers) / cm C-O hydroxy, ester 1040-1300 C=C aromatic compound, alkene 1500-1680C=O amide carbonyl, carboxyl ester C-H alkane 2850-2950 N-H amine, amide 3300-3500O-H carboxyl hydroxy What is P? A propanal B propanone C propan-1-ol D propan-2-ol Important values, constants and standards molar gas constant R = 8.31J Kmol C molmol-19 molar volume of gas V m = 22.4 dmmol at s.t.p. (101 kPa and 273 K) m = 24.0 dmmol at room conditions ionic product of water K-14mol specific heat capacity of water c = 4.18 kJ kg (4.18 J g To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Group The Periodic Table of Elements hydrogen 1.0 He helium 4.0 1213 14 15 16 17 18 3 4 5 6 7 8 9 10 11 123Li lithium 6.9 beryllium 9.0 atomic number atomic symbolKey name relative atomic mass sodium 23.0 magnesium 24.3 potassium 39.1 calcium 40.1 rubidium 85.5 strontium 87.6 caesium 132.9 barium 137.3 francium Ra radium boron 10.8 13 Al aluminium 27.0 31 Ga gallium 69.7 49 In indium 114.8 thallium 204.4 carbon 12.0 14 Si silicon 28.1 32 Ge germanium 72.6 50 Sntin 118.7 82 Pb lead 207.2 titanium 47.9 40 Zr zirconium 91.2 72 Hf hafnium 178.5 rutherfordium vanadium 50.9 41 Nb niobium 92.9 73 Ta tantalum 180.9 105 Db dubnium chromium 52.0 42 Mo molybdenum 95.9 74 W tungsten 183.8 106 Sg seaborgium manganese 54.9 43 Tc technetium rhenium 186.2 107 Bh bohrium iron 55.8 44 Ru ruthenium 101.1 76 Os osmium 190.2 108 Hs hassium Co cobalt 58.9 45 Rh rhodium 102.9 iridium 192.2 109 Mt meitnerium nickel 58.7 46 Pd palladium 106.4 platinum 195.1 11 0 Ds darmstadtium copper 63.5 47 Ag silver 107.9 79 Au gold 197.0 111 Rg roentgenium zinc 65.4 48 Cd cadmium 112.4 80 Hg mercury 200.6 11 2 Cn copernicium 11 4 flerovium 11 6 livermorium nitrogen 14.0 phosphorus 31.0 33 As arsenic 74.9 51 Sb antimony 121.8 bismuth 209.0 oxygen 16.0 sulfur 32.1 34 Se selenium 79.0 52 Te tellurium 127.6 84 Po polonium fluorine 19.0 17 Cl chlorine 35.5 35 Br bromine 79.9 iodine 126.9 Ne neon 20.2 18 Ar argon 39.9 36 Kr krypton 83.8 54 Xe xenon 131.3 86 Rn radon 11 3 nihonium 11 5 moscovium 11 7 tennessine 11 8 oganesson scandium 45.0 yttrium 88.9 57-71 lanthanoids 89-103 actinoids 57La lanthanum 138.9 89 Ac lanthanoids actinoids actinium Ce cerium 140.1 90 Th thorium 232.0 praseodymium 140.9 91 Pa protactinium 231.0 neodymium 144.4 uranium 238.0 promethium neptunium samarium 150.4 94 Pu plutonium europium 152.0 95 Am americium gadolinium 157.3 96 Cm curium terbium 158.9 97 Bk berkelium dysprosium 162.5 californium holmium 164.9 99 Es einsteinium erbium 167.3 100 Fm fermium Tm thulium 168.9 101 Md mendelevium ytterbium 173.1 102 No nobelium lutetium 175.0 lawrencium