Cambridge A Level Chemistry 9701 — 2006 May/June Paper 1 · Variant 1

1 N2O4 is a poisonous gas. It can be disposed of safely by reaction with sodium hydroxide. N2O4(g) + 2NaOH(aq) → NaNO3(aq) + NaNO2(aq) + H2O(l) What is the minimum volume of 0.5 mol dm–3 NaOH(aq) needed to dispose of 0.02 mol of N2O4? A 8 cm3 B 12.5 cm3 C 40 cm3 D 80 cm3

Mark scheme: D

More questions on Reacting masses and volumes (of solutions and gases)

2 A sample of chlorine containing isotopes of mass numbers 35 and 37 was analysed in a mass-spectrometer. How many peaks corresponding to Cl were recorded? + 2 A 2 B 3 C 4 D 5

Mark scheme: B

More questions on Mass spectrometry

3 Gallium nitride, GaN, could revolutionise the design of electric light bulbs because only a small length used as a filament gives excellent light at low cost. Gallium nitride is an ionic compound containing the Ga3+ ion. What is the electron arrangement of the nitrogen ion in gallium nitride? A 1s2 2s2 B 1s2 2s2 2p3 C 1s2 2s2 2p4 D 1s2 2s2 2p6

Mark scheme: D

More questions on Electrons, energy levels and atomic orbitals

4 A radioactive isotope of thallium, 201 81 Tl, is used to assess damage in heart muscles after a heart attack. Which statement about 201 81 Tl is correct? A This isotope has a nucleon number of 120. B The number of electrons in one atom of this isotope is 81. C The number of neutrons in one atom of this isotope is 201. D 201 X is an isotope of 201 81 Tl. 82

Mark scheme: B

More questions on Particles in the atom and atomic radius

5 In which process are hydrogen bonds broken? A H2(l) → H2(g) B NH3(l) → NH3(g) C 2HI(g) → H2(g) + I2(g) D CH4(g) → C(g) + 4H(g)

Mark scheme: B

More questions on Intermolecular forces, electronegativity and bond properties

6 Which of the following least resembles an ideal gas? A ammonia B helium C hydrogen D trichloromethane

Mark scheme: A

More questions on The gaseous state: ideal and real gases and pV = nRT

7 The diagram shows part of the lattice structures of solids X and Y. [In X, represent particles of different elements.] X Y What are the types of bonding present in X and Y? X Y A covalent metallic B ionic covalent C ionic metallic D metallic ionic

Mark scheme: B

More questions on Bonding and structure

8 In the conversion of compound X into compound Z, it was found that the reaction proceeded by way of compound Y, which could be isolated. The following steps were involved. X → Y ; ∆H, positive Y → Z ; ∆H, negative Which reaction profile fits these data? A B C D Y Y Y energy energy energy energy X Z X X Y Z Z X Z progress of progress of progress of progress of reaction reaction reaction reaction

Mark scheme: A

More questions on Enthalpy change, ΔH

9 The nickel-cadmium rechargeable battery is based upon the following overall reaction. Cd + 2NiOOH + 4H2O → Cd(OH)2 + 2Ni(OH)2.H2O What is the oxidation number of nickel at the beginning and at the end of the reaction? beginning end A +1.5 +2 B +2 +3 C +3 +2 D +3 +4

Mark scheme: C

More questions on Redox processes: electron transfer and changes in oxidation number (oxidation state)

10 At a total pressure of 1.0 atm, dinitrogen tetraoxide is 50 % dissociated at a temperature of 60 oC, according to the following equation. N2O4 2NO2 What is the value of the equilibrium constant, Kp, for this reaction at 60 oC? A 1/3 atm B 2/3 atm C 4/3 atm D 2 atm

Mark scheme: C

More questions on Chemical equilibria: reversible reactions, dynamic equilibrium

11 Swimming pool water can be kept free of harmful bacteria by adding aqueous sodium chlorate(I), NaOCl. This reacts with water to produce HOCl molecules which kill bacteria. OCl –(aq) + H2O OH–(aq) + HOCl (aq) In bright sunshine, the OCl – ion is broken down by ultra-violet light. OCl –(aq) + uv light → Cl –(aq) + ½O2(g) Which method would maintain the highest concentration of HOCl (aq)? A acidify the pool water B add a solution of chloride ions C add a solution of hydroxide ions D bubble air through the water

Mark scheme: A

More questions on Chemical equilibria: reversible reactions, dynamic equilibrium

12 Which solid-line curve most accurately represents the distribution of molecular speeds in a gas at 500 K if the dotted-line curve represents the corresponding distribution for the same gas at 300 K? A B fraction of fraction of molecules molecules speed speed C D fraction of fraction of molecules molecules speed speed

Mark scheme: C

More questions on Effect of temperature on reaction rates and the concept of activation energy

13 In which pair is the radius of the second atom greater than that of the first atom? A Na, Mg B Sr, Ca C P, N D Cl, Br

Mark scheme: D

More questions on Particles in the atom and atomic radius

14 The oxide and chloride of an element X are separately mixed with water. The two resulting solutions have the same effect on litmus. What is element X? A sodium B magnesium C aluminium D phosphorus

Mark scheme: D

More questions on Periodicity of chemical properties of the elements in Period 3

15 Aluminium chloride sublimes at 178 oC. Which structure best represents the species in the vapour at this temperature? A B C D Cl Cl Cl Cl Cl Cl Al + 3Cl Al 3+(Cl –)3 Al Al Al Al Cl Cl Cl Cl Cl Cl

Mark scheme: A

More questions on Covalent bonding and coordinate (dative covalent) bonding

16 Use of the Data Booklet is relevant to this question. What 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

Mark scheme: C

More questions on Reacting masses and volumes (of solutions and gases)

17 What happens when chlorine is bubbled through aqueous potassium iodide? A Chlorine is oxidised to chloride ions. B Hydrochloric acid is formed. C Iodide ions are oxidised to iodine. D Potassium iodide is reduced to iodine.

Mark scheme: C

More questions on The chemical properties of the halogen elements and the hydrogen halides

18 The emissions from a power station contain about 14 tonnes of SO2 per hour from the oxidation of FeS2 contained in the coal. What is the most practical way of preventing the SO2 from being released into the atmosphere? A Cool the gases and the SO2 will liquefy and can be removed. B Dissolve the ionic FeS2 in hexane. C Pass the emissions through a bed of calcium oxide. D Pass the gases through concentrated sulphuric acid to dissolve the SO2.

Mark scheme: C

More questions on Nitrogen and sulfur

19 The gaseous oxides of nitrogen have positive enthalpy changes of formation. Which factor is likely to make the most significant contribution to these enthalpy changes? A the high bond energy of the nitrogen molecule, N2 B the high electron affinity of nitrogen atoms C the high electron affinity of oxygen atoms D the similarity of the electronegativities of oxygen and nitrogen

Mark scheme: A

More questions on Enthalpy change, ΔH

20 A new industrial preparation of ethyl ethanoate has been developed using cheap sources of ethanol. Cu catalyst Cu catalyst CH3CH2OH CH3CHO CH3CH(OH)OCH2CH3 – H2 + CH3CH2OH Cu catalyst – H2 CH3CO2CH2CH3 Which process is involved at some stage in this reaction sequence? A disproportionation B electrophilic addition C nucleophilic addition D reduction

Mark scheme: C

More questions on Organic synthesis

21 Warfarin is used as a rat poison. O O C C C CH CH2 C CH3 OH O warfarin How many chiral centres are present in the warfarin molecule? A 0 B 1 C 2 D 3

Mark scheme: B

More questions on Isomerism: structural isomerism and stereoisomerism

22 The structures below show isomers of C6H12. 1 2 3 4 CH3 CH3 CH3 C2H5 C2H5 H C2H5 CH3 C C C C C C C C H C2H5 H CH3 CH3 CH3 H CH3 In which pair are the members cis-trans isomers of each other? A 1 and 2 B 1 and 3 C 1 and 4 D 2 and 4

Mark scheme: A

More questions on Isomerism: structural isomerism and stereoisomerism

23 Use of the Data Booklet is relevant to this question. In which reaction is the relative molecular mass of the organic product the largest? A bromoethane + aqueous sodium hydroxide B bromoethane + alcoholic sodium hydroxide C ethane + bromine D ethanol + phosphorus pentachloride

Mark scheme: C

More questions on Halogenoalkanes

24 Light initiates the following reaction. alkane + chlorine → chloroalkane + hydrogen chloride What happens to chlorine in this photochemical reaction? A heterolytic fission to give an electrophile B homolytic fission to give an electrophile C heterolytic fission to give a free radical D homolytic fission to give a free radical

Mark scheme: D

More questions on Alkanes

25 High-energy irradiation in the stratosphere produces radicals from chlorofluoroalkanes, commonly known as CFCs. Which radical could result from this irradiation of CHFClCF2Cl? A CHFClCFCl B CHClCF2Cl C CHFCF2Cl D CFClCF2Cl

Mark scheme: C

More questions on Alkanes

26 Which reagent could detect the presence of alcohol in a petrol consisting mainly of a mixture of alkanes and alkenes? A Na B Br2 (in CCl4) C KMnO4(aq) D 2,4-dinitrophenylhydrazine

Mark scheme: A

More questions on Alcohols

27 Which alcohol may be oxidised to a product which reacts with 2,4-dinitrophenylhydrazine reagent but not with Fehling’s reagent? A butan-1-ol B butan-2-ol C 2-methylpropan-1-ol D 2-methylpropan-2-ol

Mark scheme: B

More questions on Aldehydes and ketones

28 The first stage in the synthesis of antipyrine, a drug used in reducing fever, is the reaction between compound P and phenylhydrazine. CH3COCH2CO2CH2CH3 + NHNH2 Q P phenylhydrazine What is the product Q of this first stage? A CH3COCH2CONH B NHCH2CO2CH2CH3 C CH3COCH2CO NHNH2 D NHN CH3CCH2CO2CH2CH3

Mark scheme: D

More questions on Characteristic organic reactions

29 Aldehydes and ketones are carbonyl compounds. Which of them react both with NaBH4 and with Tollens’ reagent? A both aldehydes and ketones B aldehydes only C ketones only D neither aldehydes nor ketones

Mark scheme: B

More questions on Aldehydes and ketones

30 Which compound is a product of the hydrolysis of CH3CO2C3H7 by boiling aqueous sodium hydroxide? A CH3OH B C3H7OH C C3H7CO2H D C H CO −Na + 3 7 2

Mark scheme: B

More questions on Esters

31 The Group IV elements carbon, silicon and germanium all exist in a diamond structure. The bond lengths in these structures are given below. element X C Si Ge bond length X–X / nm 0.154 0.234 0.244 Why does the bond length increase down the group? 1 Orbital overlap decreases down the group. 2 Atomic radius increases down the group. 3 Nuclear charge increases down the group.

Mark scheme: B

More questions on Particles in the atom and atomic radius

32 Sodium ions can be formed from sodium atoms. Na(s) → Na+(g) Which quantities are required to calculate the enthalpy change of formation of gaseous sodium ions? 1 enthalpy change of atomisation of sodium 2 first ionisation energy of sodium 3 enthalpy change of formation of sodium

Mark scheme: B

More questions on Ionisation energy

33 Hydrazine, N2H4, is widely used as a rocket fuel because it reacts with oxygen as shown, producing ‘environmentally friendly’ gases. N2H4(l) + O2(g) → N2(g) + 2H2O(g) ∆H = –534 kJ mol–1 Despite its use as a rocket fuel, hydrazine does not spontaneously burn in oxygen. Why does hydrazine not burn spontaneously? 1 The activation energy is too high. 2 The N≡N bond is very strong. 3 Hydrazine is a liquid.

Mark scheme: D

More questions on Effect of temperature on reaction rates and the concept of activation energy

34 Compound X • does not conduct electricity when in a liquid state, • when added to water produces a solution that readily conducts electricity. What could X be? 1 MgCl2 2 SiCl4 3 PCl3

Mark scheme: C

More questions on Ionic bonding

35 Hydroxyapatite, a basic calcium phosphate, Ca(OH)2.3Ca3(PO4)2, is the mineral found in bone. In older people, calcium ions can be lost from the hydroxyapatite, weakening the bone structure. In such cases, strontium salts are administered to strengthen the bone. The strontium ions replace the lost calcium ions in the hydroxyapatite. Which statements are correct? 1 Strontium ions are nearly the same size as calcium ions and so may easily replace them in the hydroxyapatite. 2 Strontium hydroxide is less soluble than calcium hydroxide and so will precipitate better in the bone structure. 3 There is ionic, covalent and metallic bonding in hydroxyapatite which gives it strength.

Mark scheme: D

More questions on Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds

36 Ammonia and chlorine react in the gas phase. 8NH3 + 3Cl2 → N2 + 6NH4Cl Which statements are correct? 1 Ammonia behaves as a reducing agent. 2 Ammonia behaves as a base. 3 The oxidation number of the hydrogen changes.

Mark scheme: B

More questions on Redox processes: electron transfer and changes in oxidation number (oxidation state)

37 In which pairs are the members stereoisomers of each other? 1 CH3 CH3 C C Br Br H Cl Cl H 2 CH3 Br Br CH3 C C C C H H H H 3 CH3 Br CH3 H C C C C H Cl Br Cl

Mark scheme: D

More questions on Isomerism: structural isomerism and stereoisomerism

38 Deuterium, D, is the H 2 isotope of hydrogen. DBr has the same chemical properties as HBr. 1 Which compounds could be made by the reaction of DBr with another compound in a single reaction? Br D 1 2 CHBr2CHDBr OD 3 CH3CH Br

Mark scheme: B

More questions on Alkenes

39 How can the rate of reaction between ethanal and aqueous hydrogen cyanide be increased? 1 by irradiation with ultraviolet light 2 by a rise in temperature 3 by the addition of a small quantity of aqueous sodium cyanide

Mark scheme: C

More questions on Effect of temperature on reaction rates and the concept of activation energy

40 Which statements about lactic acid, CH3CH(OH)CO2H, are correct? 1 Lactic acid forms optical isomers. 2 Two hydrogen atoms per lactic acid molecule can be involved in hydrogen bonding. 3 Lactic acid would form an aldehyde when oxidised by acidified potassium dichromate(VI).

Mark scheme: B

More questions on Isomerism: optical