Cambridge A Level Chemistry 9701 — 2010 Oct/Nov Paper 1 · Variant 2

Question 1

1 The ability of an atom in a covalent bond to attract electrons to itself is called its electronegativity. The greater the difference between the electronegativities of the two atoms in the bond, the more polar is the bond. Which pair will form the most polar covalent bond between the atoms? A chlorine and bromine B chlorine and iodine C fluorine and chlorine D fluorine and iodine

Accepted Answer

D

Question 2

2 Which diagram correctly represents the Boltzmann distribution of molecular energies at two temperatures T1 and T2, where T1 = 300 K and T2 = 310 K? A B T1 T2 T1 proportion proportion T2 of molecules of molecules 0 molecular 0 molecular energy energy C D T2 T1 T2 T1 proportion proportion of molecules of molecules 0 molecular 0 molecular energy energy

Accepted Answer

B

Question 3

3 The table gives the radii, in pm, of some ions. [1 pm = 10–12 m] ion radii Na+ 102 Mg2+ 72 Cs+ 167 Cl – 181 O2– 140 Caesium chloride, CsCl, has a different lattice structure from both sodium chloride, NaCl, and magnesium oxide, MgO. CsCl lattice NaCl and MgO lattice Which factor appears to determine the type of lattice for these three compounds? A the charge on the cation B the ratio of the ionic charges C the ratio of the ionic radii D the sum of the ionic charges

Accepted Answer

C

Question 4

4 Methanol may be prepared by the reaction between carbon monoxide and hydrogen. CO(g) + 2H2(g) → CH3OH(g) The relevant average bond energies are given below. E(C≡O) 1077 kJ mol–1 E(C–O) 360 kJ mol–1 E(C–H) 410 kJ mol–1 E(H–H) 436 kJ mol–1 E(O–H) 460 kJ mol–1 What is the enthalpy change of this reaction? A –537 kJ mol–1 B –101 kJ mol–1 C +101 kJ mol–1 D +537 kJ mol–1

Accepted Answer

B

Question 5

5 Which solid has a simple molecular lattice? A calcium fluoride B nickel C silicon(IV) oxide D sulfur

Accepted Answer

D

Question 6

6 The reaction pathway diagram below illustrates the energies of reactants, products and the transition state of a reaction. transition state E1 E2 energy reactants E3 products reaction coordinate Which expression represents the activation energy of the forward reaction? A E1 – E2 B E1 – E3 C E2 – E3 D (E1 – E2) – (E2 – E3)

Accepted Answer

A

Question 7

7 Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa pressure. If the flasks are connected at constant temperature, what is the final pressure? A 8 kPa B 9 kPa C 10 kPa D 11 kPa

Accepted Answer

A

Question 8

8 Use of the Data Booklet is relevant to this question. The enthalpy change of formation, ∆Hf, of hydrated calcium ions is the enthalpy change of the following reaction. Ca(s) + aq – 2e– → Ca2+(aq) The following enthalpy changes are not quoted in the Data Booklet. Ca(s) → Ca(g) ∆Ha = 177 kJ mol–1 Ca2+(g) + aq → Ca2+(aq) ∆Hhyd = –1565 kJ mol–1 What is the enthalpy change of formation of hydrated calcium ions? A –1388 kJ mol–1 B –798 kJ mol–1 C –238 kJ mol–1 D +352 kJ mol–1

Accepted Answer

D

Question 9

9 The following equilibrium is set up in a mixture of concentrated nitric and sulfuric acids. HNO3 + H2SO4 H2NO3 + + HSO4 – Which row correctly describes the behaviour of each substance in the equilibrium mixture? HNO3 H2SO4 H2NO3 + HSO4 – A acid acid base base B acid base base acid C base acid acid base D base acid base acid

Accepted Answer

C

Question 10

10 Which molecule or structure does not contain three atoms bonded at an angle between 109° and 110°? A ethanoic acid B graphite C propane D silicon(IV) oxide

Accepted Answer

B

Question 11

11 A dimer, X, is stable when solid but a dynamic equilibrium is set up in solution. X(aq) 2Y(aq) A solution of X has an initial concentration of 0.50 mol dm–3. When equilibrium has been reached [X(aq)] has fallen to 0.25 mol dm–3. The changes in [X(aq)] and [Y(aq)] are plotted against time until equilibrium is reached. The value of Kc is then calculated. Which graph and value for Kc are correct? graph Kc / mol dm–3 0.5 X 0.4 concentration 0.3 A 1 / mol dm–3 0.2 0.1 Y 0 0 time 0.5 X 0.4 0.3 2 concentration B / mol dm–3 0.2 0.1 Y 0 0 time 0.5 X 0.4 1 concentration 0.3 C / mol dm–3 0.2 Y 0.1 0 0 time 0.5 2 X 0.4 concentration 0.3 D / mol dm–3 0.2 Y 0.1 0 0 time

Accepted Answer

C

Question 12

12 Equimolar quantities of magnesium carbonate and strontium carbonate are separately heated to bring about complete thermal decomposition. The minimum temperature for this to occur is called Td. The cold residues are separately added to equal volumes of water and the change in pH is measured. The change in pH is called ∆pH. Which metal has the higher value of Td, and the greater value of ∆pH? Td ∆pH A Mg Mg B Mg Sr C Sr Mg D Sr Sr

Accepted Answer

D

Question 13

13 In aqueous solution, the acid HIO disproportionates according to the following equation where m, n, p and q are simple whole numbers in their lowest ratios. mHIO → nI2 + pHIO3 + qH2O This equation can be balanced using oxidation numbers. What are the values for n and p? n p A 1 2 B 2 1 C 4 1 D 4 2

Accepted Answer

B

Question 14

14 Use of the Data Booklet is relevant to this question. Which mass of solid residue can be obtained from the thermal decomposition of 4.10 g of anhydrous calcium nitrate? A 0.70 g B 1.00 g C 1.40 g D 2.25 g

Accepted Answer

C

Question 15

15 Which statement explains the observation that magnesium hydroxide dissolves in aqueous ammonium chloride, but not in aqueous sodium chloride? A The ionic radius of the NH4 + ion is similar to that of Mg2+ but not that of Na+. B NH4Cl dissociates less fully than NaCl. C The Na+ and Mg2+ ions are isoelectronic (have the same number of electrons). D The NH4 + ion can donate a proton.

Accepted Answer

D

Question 16

16 What happens when chlorine is bubbled through aqueous potassium iodide? A Chlorine is oxidised to chlorate(V) ions. B Chlorine is oxidised to chloride ions. C Iodide ions are oxidised to iodine. D There is no observable reaction.

Accepted Answer

C

Question 17

17 Strontium metal can be obtained by the electrolysis of molten strontium bromide, SrBr2, using the apparatus shown in the diagram. steel cathode atmosphere of argon graphite anode molten strontium molten strontium bromide heat Why is an atmosphere of argon used around the cathode? A A thin film of a compound of strontium and argon forms on the surface protecting the freshly formed metal. B The argon keeps the strontium molten. C The argon stops the molten strontium rising too high in the tube. D Without the argon, strontium oxide would form in the air.

Accepted Answer

D

Question 18

18 Which statement about bromine is correct? A Bromine is insoluble in non-polar solvents. B Bromine vapour is more dense than air. C Bromine will not vapourise significantly under normal conditions. D Gaseous bromine is purple.

Accepted Answer

B

Question 19

19 Concentrated sulfuric acid reacts with both solid sodium chloride at room temperature and with solid sodium iodide at room temperature. Which row correctly describes how concentrated sulfuric acid behaves in each of these reactions? with sodium chloride with sodium iodide A as an oxidising agent only as an oxidising agent only B as a strong acid and as an oxidising agent as a strong acid only C as a strong acid only as a strong acid and as an oxidising agent D as a strong acid only as a strong acid only

Accepted Answer

C

Question 20

20 How many structural isomers are there of trichloropropane, C3H5Cl 3? A 3 B 4 C 5 D 6

Accepted Answer

C

Question 21

21 Nine compounds have molecular formula C4H8Br2. Which compound may be synthesised from an alkene by an addition reaction? A 1,1-dibromobutane B 1,2-dibromobutane C 1,3-dibromobutane D 1,3-dibromomethylpropane

Accepted Answer

B

Question 22

22 When ethanal, CH3CHO, reacts with HCN and the organic product is hydrolysed by aqueous acid, organic compound Y is formed. When propanal, C2H5CHO, is heated under reflux with acidified potassium dichromate(VI), organic compound Z is formed. What is the difference in relative molecular mass of compounds Y and Z? A 12 B 14 C 16 D 17

Accepted Answer

C

Question 23

23 Which sequence of reagents may be used in the laboratory to convert propan-1-ol into 2-bromopropane? A concentrated sulfuric acid, followed by bromine B concentrated sulfuric acid, followed by hydrogen bromide C ethanolic sodium hydroxide, followed by bromine D ethanolic sodium hydroxide, followed by hydrogen bromide

Accepted Answer

B

Question 24

24 Esters are frequently used as solvents and as flavouring agents in fruit drinks and confectionery. An ester C8H12Br2O4 can be prepared in low yield by the reaction shown. CH3C(Br)(CH2Br)CO2H + (CH3)2C(OH)CO2H ⇌ C8H12Br2O4 + H2O What is the structural formula of the ester C8H12Br2O4? A CH3C(Br)(CH2Br)CO2C(CH3)2CO2H B CH3C(Br)(CH2Br)CO2C(OH)(CH3)CO2CH3 C CH3C(Br)(CH3)CO2C(CH3)2CO2CH2Br D (CH3)2C(Br)C(CO2H)(CH2Br)CO2CH3

Accepted Answer

A

Question 25

25 Many, but not all, organic reactions need to be heated before reaction occurs. Which reaction occurs at a good rate at room temperature (20 °C)? A C10H22 → C8H18 + C2H4 B CH3CH2CH2Br + NH3 → CH3CH2CH2NH2 + HBr C CH3CH2OH + KBr → CH3CH2Br + KOH D (CH3)2CO + H2NNHC6H3(NO2)2 → (CH3)2C=NNHC6H3(NO2)2 + H2O

Accepted Answer

D

Question 26

26 Which pair of reagents will take part in a redox reaction? A CH3CH2OH + concentrated H2SO4 B CH3CHO + Tollens’ reagent C CH3CO2C2H5 + dilute H2SO4 D CH3COCH3 + Fehling’s solution

Accepted Answer

B

Question 27

27 Part of the structure of strobilurin, a fungicide, is shown. R and R' are inert groups. O OCH3 R' R If strobilurin is first warmed with aqueous sulfuric acid, and its product then treated with hydrogen in the presence of a palladium catalyst, what could be the structure of the final product? A B O OH HO OCH3 R' R' R R C D OH O OH OH OH R' R' R R OH

Accepted Answer

A

Question 28

28 Fluoroalkenes are used to make polymers such as poly(vinyl)fluoride (PVF). PVF is used to make non-flammable interiors for aircraft. The diagram shows the repeat unit of the polymer PVF. H H C C H F What is the skeletal formula of the monomer of PVF? H F F F F A B C D H H

Accepted Answer

B

Question 29

29 CH3CH2COCH2CH3 reacts with hydrogen cyanide to form a cyanohydrin. Which feature applies to the product? A It has one chiral centre. B It is formed by electrophilic addition. C It is formed via a C–OH intermediate. D Its formation requires the use of cyanide ions as a catalyst.

Accepted Answer

D

Question 30

30 Which of the compounds shown have chiral carbon atoms? 1 2 3 4 OH O CH3 CH3 CH3 CH3 OH A 1, 2, 3 and 4 B 1 and 4 only C 2 and 3 only D 2, 3 and 4 only

Accepted Answer

D

Question 31

31 When ammonia, NH3, is produced in a school or college laboratory, it is usually dried before being collected. Which drying agents may be used to dry ammonia? 1 calcium oxide, CaO 2 phosphorus(V) oxide, P4O10 3 concentrated sulfuric acid, H2SO4

Accepted Answer

D

Question 32

32 Zirconium, Zr, proton number 40, is a metal which is used in corrosion-resistant alloys. Zirconium metal is extracted from the oxide ZrO2 by the following sequence of reactions. reaction 1 ZrO2 + 2Cl 2 + 2C → ZrCl 4 + 2CO reaction 2 ZrCl 4 + 2Mg → Zr + 2MgCl 2 Which statements about this extraction process are correct? 1 Carbon in reaction 1 behaves as a reducing agent. 2 Magnesium in reaction 2 behaves as a reducing agent. 3 Chlorine in reaction 1 behaves as a reducing agent.

Accepted Answer

B

Question 33

33 Which statements about covalent bonds are correct? 1 A triple bond consists of one π bond and two σ bonds. 2 The electron density in a σ bond is highest along the axis between the two bonded atoms. 3 A π bond restricts rotation about the σ bond axis.

Accepted Answer

C

Question 34

34 A student puts 10 cm3 of 0.100 mol dm–3 sulfuric acid into one test-tube and 10 cm3 of 0.100 mol dm–3 ethanoic acid into another test-tube. He then adds 1.0 g (an excess) of magnesium ribbon to each test-tube and takes suitable measurements. Both acids have the same starting temperature. Neither reaction is complete after 2 minutes, but both are complete after 20 minutes. Which statements are correct? 1 After 2 minutes, the sulfuric acid is at a higher temperature than the ethanoic acid. 2 After 2 minutes, the sulfuric acid has produced more gas than the ethanoic acid. 3 After 20 minutes, the sulfuric acid has produced more gas than the ethanoic acid.

Accepted Answer

A

Question 35

35 In which ways are the main reactions in the Haber and Contact processes similar? 1 A higher yield is favoured by higher pressures. 2 The reaction is a redox process. 3 The forward reaction is exothermic.

Accepted Answer

A

Question 36

36 A car burning lead-free fuel has a catalytic converter fitted to its exhaust. On analysis its exhaust gases are shown to contain small quantities of nitrogen oxides. Which modifications would result in lower exhaust concentrations of nitrogen oxides? 1 an increase in the surface area of the catalyst in the converter 2 an increase in the rate of flow of the exhaust gases through the converter 3 a much higher temperature of combustion in the engine

Accepted Answer

D

Question 37

37 The diagram shows a compound present in smoke from burning garden waste. H H H C C C O H Which reagents would undergo a colour change on reaction with this compound? 1 aqueous bromine 2 Fehling’s reagent 3 warm acidified K2Cr2O7

Accepted Answer

A

Question 38

38 Organic acids and alcohols react together to form esters. Which pairs of compounds could produce a product of molecular formula C4H6O4? 1 CH3CO2H and C2H5OH 2 HCO2H and HOCH2CH2OH 3 HO2CCO2H and CH3OH

Accepted Answer

C

Question 39

39 Use of the Data Booklet is relevant for this question. In an organic synthesis, a 62 % yield of product is achieved. Which of these conversions are consistent with this information? 1 74.00g of butan-2-ol → 44.64 g of butanone 2 74.00g of butan-1-ol → 54.56 g of butanoic acid 3 74.00g of 2-methylpropan-1-ol → 54.56 g of 2-methylpropanoic acid

Accepted Answer

A

Question 40

40 A reaction pathway diagram is shown. energy reaction pathway Which reactions would have such a profile? 1 (CH3)3CBr + NaOH → (CH3)3COH + NaBr 2 CH3CH2Br + NaOH → CH3CH2OH + NaBr 3 (CH3)3CCH2CH2Cl + 2NH3 → (CH3)3CCH2CH2NH2 + NH4Cl

Accepted Answer

D

Question paper16 pages

Mark scheme2 pages

Questions as text

Q1 · The ability of an atom in a covalent bond to attract electrons to itself is called its…

Q2 · Which diagram correctly represents the Boltzmann distribution of molecular energies at…

Q3 · The table gives the radii, in pm, of some ions

Q4 · Methanol may be prepared by the reaction between carbon monoxide and hydrogen

Q5 · Which solid has a simple molecular lattice?

Q6 · The reaction pathway diagram below illustrates the energies of reactants, products and…

Q7 · Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon…

Q8 · Use of the Data Booklet is relevant to this question

Q9 · The following equilibrium is set up in a mixture of concentrated nitric and sulfuric acids

Q10 · Which molecule or structure does not contain three atoms bonded at an angle between 109°…

Q11 · A dimer, X, is stable when solid but a dynamic equilibrium is set up in solution

Q12 · Equimolar quantities of magnesium carbonate and strontium carbonate are separately heated…

Q13 · In aqueous solution, the acid HIO disproportionates according to the following equation…

Q14 · Use of the Data Booklet is relevant to this question

Q15 · Which statement explains the observation that magnesium hydroxide dissolves in aqueous…

Q16 · What happens when chlorine is bubbled through aqueous potassium iodide?

Q17 · Strontium metal can be obtained by the electrolysis of molten strontium bromide, SrBr2…

Q18 · Which statement about bromine is correct?

Q19 · Concentrated sulfuric acid reacts with both solid sodium chloride at room temperature and…

Q20 · How many structural isomers are there of trichloropropane, C3H5Cl 3?

Q21 · Nine compounds have molecular formula C4H8Br2

Q22 · When ethanal, CH3CHO, reacts with HCN and the organic product is hydrolysed by aqueous…

Q23 · Which sequence of reagents may be used in the laboratory to convert propan-1-ol into…

Q24 · Esters are frequently used as solvents and as flavouring agents in fruit drinks and…

Q25 · Many, but not all, organic reactions need to be heated before reaction occurs

Q26 · Which pair of reagents will take part in a redox reaction?

Q27 · Part of the structure of strobilurin, a fungicide, is shown

Q28 · Fluoroalkenes are used to make polymers such as poly(vinyl)fluoride (PVF)

Q29 · CH3CH2COCH2CH3 reacts with hydrogen cyanide to form a cyanohydrin

Q30 · Which of the compounds shown have chiral carbon atoms?

Q31 · When ammonia, NH3, is produced in a school or college laboratory, it is usually dried…

Q32 · Zirconium, Zr, proton number 40, is a metal which is used in corrosion-resistant alloys

Q33 · Which statements about covalent bonds are correct?

Q34 · A student puts 10 cm3 of 0.100 mol dm–3 sulfuric acid into one test-tube and 10 cm3 of…

Q35 · In which ways are the main reactions in the Haber and Contact processes similar?

Q36 · A car burning lead-free fuel has a catalytic converter fitted to its exhaust

Q37 · The diagram shows a compound present in smoke from burning garden waste

Q38 · Organic acids and alcohols react together to form esters

Q39 · Use of the Data Booklet is relevant for this question

Q40 · A reaction pathway diagram is shown

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