Chemistry 9701/13 October/November 2021: question paper and mark scheme

Question

The mass spectrum of a sample of neon is shown. The relative abundance of each peak is written in brackets above it. (100) relative abundance (8) (0.3) 20 21 22 mass charge What is the relative atomic mass, Ar, of this sample of neon? A 20.15 B 20.20 C 21.00 D 21.82

Question

2.0 g of ammonium nitrate, NH4NO3, decomposes to give 0.90 g of water and a single gas. What is the identity of the gas? A NO B NO2 C N2O D N2

Question

Which of these elements has the highest fifth ionisation energy? A C B N C P D Si

Question

The ion X2+ has the same electronic configuration as the atom Kr. What is the electronic configuration of an atom of X? A [Ar] 4s23d104p6 B [Ar] 4s23d104p65s2 C [Ar] 4s24d104p6 D [Ar] 4s24d104p65s2

Question

Which type of interaction exists between water molecules and metal cations in aqueous solution? A dipole-dipole interactions B hydrogen bonds C ion-dipole interactions D ionic bonds

Question

Which substance shows the greatest deviation from the properties of an ideal gas under room conditions? A CO2(g) B H2(g) C Ne(g) D NH3(g)

Question

In order to determine the enthalpy of neutralisation of a strong acid and a strong alkali, 25.0 cm3 of 2.00 mol dm‒3 sodium hydroxide is added to 25.0 cm3 of 2.00 mol dm‒3 hydrochloric acid. The increase in temperature is 12 °C. In a second experiment, the same method is used, but 50.0 cm3 of 2.00 mol dm‒3 sodium hydroxide is added to 50.0 cm3 of 2.00 mol dm‒3 hydrochloric acid. What is the increase in temperature in the second experiment? A 6 °C B 12 °C C 24 °C D 48 °C

Question

Which equation represents the enthalpy change of atomisation of iodine? A 1 I (g) 2 2 → I(g) B I2(g) → 2I(g) C 1 I (s) 2 2 → I(g) D I2(s) → 2I(g)

Question

Zinc atoms can be oxidised to Zn2+ ions by dichromate(VI) ions in acid solution. Chromium is reduced to Cr3+ in this reaction. Which equation is correct? A Cr2O72– + Zn + 14H+ → 2Cr3+ + Zn2+ + 7H2O B Cr2O72– + Zn + 14H+ → 2Cr3+ + 3Zn2+ + 7H2O C Cr2O72– + 3Zn + 14H+ → 2Cr3+ + 3Zn2+ + 7H2O D 2Cr2O72– + 3Zn + 14H+ → 2Cr3+ + 3Zn2+ + 7H2O

Question

The equation shows that H2(g) and I2(g) react to form an equilibrium mixture. H2(g) + I2(g) 2HI(g) ΔH o = –9.6 kJ mol–1 A mixture containing equal amounts of H2(g) and I2(g) is made at temperature T1 and the composition of the mixture is monitored. A graph of the results is shown. 0.5 mole fraction of I2(g) 0.23 0 0 time The experiment is repeated at a lower temperature, T2. Which new graph would be obtained? A B 0.5 0.5 mole fraction mole fraction of I2(g) of I2(g) 0.23 0.23 0 0 0 time 0 time C D 0.5 0.5 mole fraction mole fraction of I2(g) of I2(g) 0.23 0.23 0 0 0 time 0 time

Question

The diagram shows the Boltzmann distribution of energies for a reactant gas. For a particular reaction, the activation energy is X. number of particles with energy, E 0 0 X energy, E Which change to the diagram occurs if an effective catalyst is added at the same temperature? A More particles will possess higher values of E. B The peak will move to the left. C The peak will move to the right. D The value of the activation energy decreases.

Question

Which element requires the least number of moles of oxygen for the complete combustion of 1 mol of its atoms? A aluminium B magnesium C phosphorus D sodium

Question

An element, Y, reacts according to the following sequence. burns an excess of in O2 HCl (aq) NaOH(aq) NaOH(aq) Y white solid solution white precipitate solution What could be element Y? A Na B Mg C Al D P

Question

In which list are all three compounds soluble in water? A barium chloride, calcium carbonate, magnesium hydroxide B barium hydroxide, calcium hydroxide, strontium carbonate C barium chloride, barium hydroxide, magnesium sulfate D barium sulfate, calcium sulfate, magnesium hydroxide

Question

Anhydrous magnesium nitrate, Mg(NO3)2, decomposes when heated, giving a white solid and a mixture of two gases, X and Y. Y is oxygen. What is the ratio mass of X released ? mass of Y released A 1 B 1 C 1 D 1 0.174 0.267 0.348 3.43

Question

In a series of nine experiments, to test the reactivity of the halogens, an aqueous solution of each halogen is added to an equal volume of an aqueous solution containing halide ions, as shown in the table. halogen halide solution solution sodium chloride (aq) sodium bromide (aq) sodium iodide (aq) chlorine (aq) experiment 1 experiment 2 experiment 3 bromine (aq) experiment 4 experiment 5 experiment 6 iodine (aq) experiment 7 experiment 8 experiment 9 The nine resulting mixtures are then shaken separately with an equal volume of hexane. The nine tubes are left to stand so that the aqueous and organic solvents separate into layers. How many test-tubes contain a purple upper hexane layer? A 1 B 2 C 3 D 5

Question

Z is a compound of sodium, chlorine and oxygen. It contains 45.1% by mass of oxygen. Z is prepared by reacting sodium hydroxide with chlorine. Which row shows the conditions used for the reaction and the oxidation state of chlorine in Z? reaction conditions oxidation state of Cl in Z A cold dilute NaOH +1 B cold dilute NaOH +5 C hot concentrated NaOH +1 D hot concentrated NaOH +5

Question

Which row is correct? shape bonds present ammonia ammonium ammonia ammonium molecule ion molecule ion A pyramidal regular tetrahedral σ σ B pyramidal regular tetrahedral σ π C regular tetrahedral pyramidal σ σ D regular tetrahedral pyramidal π σ

Question

The table describes two possible environmental consequences of adding too much ammonium nitrate fertiliser to the soil. Which row is correct? increased plant photochemical growth in rivers smog A B C D

Question

Hex-2-ene can be made by the reaction shown. H O– HO + I– I Which statement about this reaction is correct? A (CH3)3CO– is behaving as a Brønsted-Lowry base. B (CH3)3CO– is behaving as an oxidising agent. C The C–I bond breaks via homolytic fission. D This is a hydrolysis reaction.

Question

Structural isomerism only should be considered when answering this question. Molecule X contains three C=C double bonds. One mole of X is reacted with three moles of HBr. The carbon skeleton is unchanged. molecule X How many different products are formed? A 3 B 4 C 6 D 8

Question

Structural isomerism and stereoisomerism should be considered when answering this question. A colourless liquid, C5H11Cl , exists as a mixture of two optical isomers. When heated with sodium hydroxide in ethanol, a mixture of only two alkenes is formed. What could the colourless liquid be? A (CH3CH2)2CHCl B CH3CH2CH2CHCl CH3 C CH3CH2CCl (CH3)2 D (CH3)2CHCHCl CH3

Question

When 2-bromo-2-methylpropane reacts with aqueous sodium hydroxide, an alcohol is formed. Which diagram describes the first step in the reaction mechanism? A B C D CH3 CH3 CH3 CH3 G+ G– G+ G– G+ G– G+ G– H 3C C Br H 3C C Br H 3C C Br H 3C C Br – – CH3 CH3 HO•• CH3 HO•• CH3

Question

When an organic compound, Q, is treated with phosphorus pentachloride, fumes of hydrogen chloride are evolved. When Q is warmed with acidified aqueous potassium dichromate(VI), the solution turns green. What is Q? A CH3CH2CHO B CH3CH2CO2H C CH3CH(OH)CH3 D (CH3)3COH

Question

Alcohol Y gives a yellow precipitate with alkaline aqueous iodine. It can be oxidised to give a mixture of products including substance Z. Substance Z gives a red-brown precipitate with Fehling’s solution. Which alcohol could be Y? A CH3CH(OH)CH(CH3)CH2OH B CH3C(OH)(CH3)CH2CH2OH C CH3CH(OH)CH2CH(OH)CH3 D CH2(OH)CH2CH(OH)CH2CH3

Question

CH3CH2COCH2CH3 reacts with hydrogen cyanide to form an organic product called a cyanohydrin. Which statement is correct? A The cyanohydrin product has one chiral centre. B The cyanohydrin product is formed by electrophilic addition. C The cyanohydrin product is formed via an intermediate which contains a C–OH group. D The formation of the cyanohydrin product requires the use of cyanide ions as a catalyst.

Question

Reduction of compound R with LiAl H4 gives the compound 4-methylpentane-2,3-diol. What could be the identity of compound R? A B C D O O O O O O O O

Question

Citric acid is found in lemon juice. citric acid HO2CCH2C(OH)(CO2H)CH2CO2H Which volume of 0.40 mol dm–3 sodium hydroxide solution is required to neutralise a solution containing 0.0050 mol of citric acid? A 12.5 cm3 B 25.0 cm3 C 37.5 cm3 D 50.0 cm3

Question

The structural formula of an ester is (CH3)2CHOCO(CH2)2CH3. This ester is boiled with aqueous hydrochloric acid. Which two products are formed? A propan-1-ol and butanoic acid B propan-2-ol and butanoic acid C propan-1-ol and propanoic acid D propan-2-ol and propanoic acid

Question

The infra-red spectra of three organic compounds are shown. 100 transmittance / % spectrum 1 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 100 transmittance / % spectrum 2 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 100 transmittance / % spectrum 3 50 0 4000 3000 2000 1500 1000 500 wavenumber / cm–1 What could the three compounds be? spectrum 1 spectrum 2 spectrum 3 A propanoic acid propanone propan-2-ol B propanone propanoic acid propan-2-ol C propanone propan-2-ol propanoic acid D propan-2-ol propanoic acid propanone Section B For each of the questions in this section, one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct (you may find it helpful to put a tick against the statements that you consider to be correct). The responses A to D should be selected on the basis of A B C D 1, 2 and 3 1 and 2 2 and 3 1 only are only are only are is correct correct correct correct No other combination of statements is used as a correct response. Use of the Data Booklet may be appropriate for some questions.

Question

Which changes can be used to measure the rates of chemical reactions? 1 the decrease in concentration of a reactant per unit time 2 the rate of appearance of a product 3 the increase in total volume of gas per unit time at constant pressure

Question

Iron reacts with steam to produce hydrogen and an oxide of iron. 3Fe(s) + 4H2O(g) Fe3O4(s) + 4H2(g) A system containing all four substances is at equilibrium. Which changes will decrease the mass of Fe present at equilibrium? 1 addition of steam at constant pressure 2 increase in overall pressure 3 addition of an effective catalyst

Question

Ethylene glycol, HOCH2CH2OH, is used as a de-icer. It allows ice to melt at temperatures below 0 °C. Which statements are correct? 1 Ethylene glycol disrupts the extensive network of hydrogen bonds in ice. 2 Ethylene glycol molecules form hydrogen bonds with other ethylene glycol molecules. 3 Ethylene glycol molecules will dissolve in the water formed from the ice.

Question

Which molecules contain at least one unpaired electron? 1 NO 2 NO2 3 NH3

Question

Which elements form a chloride in which both covalent bonding and coordinate (dative covalent) bonding are present? 1 Al 2 Si 3 Mg

Question

Which statements about calcium oxide are correct? 1 It can be reduced by heating with magnesium. 2 It is produced when calcium nitrate is heated. 3 It reacts with cold water.

Question

A diketo acid is a compound with two ketone groups and one carboxylic acid group. limonene terpinolene Which statements about the reactions of limonene and terpinolene are correct? 1 When reacted with an excess of hydrogen and a nickel catalyst, limonene and terpinolene produce the same compound. 2 An excess of hot concentrated acidified KMnO4 reacts with limonene and with terpinolene to form different diketo acids. 3 The reactions of limonene and terpinolene with an excess of Br2 produce positional isomers with the same number of chiral carbon atoms. The responses A to D should be selected on the basis of A B C D 1, 2 and 3 1 and 2 2 and 3 1 only are only are only are is correct correct correct correct No other combination of statements is used as a correct response.

Question

One molecule of dodecane, C12H26, is cracked, producing three product molecules, X, Y and Z. X is a straight chain alkane. Y and Z are straight chain alkenes with different Mr values. Which statements about X, Y and Z are correct? 1 If Y and Z are but-1-ene and ethene respectively, X will be hexane. 2 If X is butane, then Y and Z could both show cis-trans isomerism. 3 X could be octane.

Question

Which statements about chlorofluoroalkanes are correct? 1 Both the C–Cl and C–F bonds are readily dissociated by ultra-violet light. 2 They have caused ozone depletion. 3 They are relatively chemically inert.

Question

Which reactions of propan-1-ol have water as one of the products? 1 passing propan-1-ol vapour over hot Al 2O3 2 mixing propan-1-ol with warm ethanoic acid and a few drops of concentrated sulfuric acid 3 warming propan-1-ol with HBr