Posted: September 13th, 2017

fractional distillation

1 Check that the answer sheet provided is for Chemistry Advanced Higher (Section A). 2 For this section of the examination you must use an HB pencil and, where

necessary, an eraser. 3 Check that the answer sheet you have been given has your name, date of birth, SCN (Scottish Candidate Number) and Centre Name printed on it.

Do not change any of these details. 4 If any of this information is wrong, tell the Invigilator immediately. 5 If this information is correct, print your name and seat number

in the boxes provided. 6 The answer to each question is either A, B, C or D. Decide what your answer is, then, using your pencil, put a horizontal line in the space provided (see

sample question below). 7 There is only one correct answer to each question. 8 Any rough working should be done on the question paper or the rough working sheet, not

on your answer sheet. 9 At the end of the exam, put the answer sheet for Section A inside the front cover of your answer book. Sample Question To show that the ink in a ball-pen

consists of a mixture of dyes, the method of separation would be A chromatography B fractional distillation C fractional crystallisation D filtration. The correct answer is A

—chromatography. The answer A has been clearly marked in pencil with a horizontal line (see below).

A
Changing an answer

If you decide to change your answer, carefully erase your first answer and using your pencil, fill in the answer you want. The answer below has been changed to D.

[X012/13/02]

Page two

1. Which equation can be used to represent the second ionisation energy of the diatomic element, X? A X2(g) ? X22+(g) + 2e–

6. Which of the following represents the configuration of the highest energy electrons in an atom of a Group III element in the ground state? A 3s23p1

B 3s23p3 C 4s23d1 D 4s24p3

B ½X2(g) ? X2+(g) + 2e– C X+(g) ? X2+(g) + e– D X(g) ? X2+(g) + 2e–

2. Which of the following lists electromagnetic radiation bands in order of increasing frequency? A B C

D Ultraviolet, visible, infra-red, radio Radio, infra-red, visible, ultraviolet Radio, microwave, ultraviolet, visible Visible, ultraviolet, X-ray, microwave

7. Which of the following analytical techniques would be most suitable to determine quantitatively the concentration of sodium ions in a urine sample? A

B C Mass spectrometry Infra-red spectroscopy Atomic emission spectroscopy magnetic resonance

3. Using information from the Data Booklet which one of the following metal salts will emit radiation of the highest frequency when placed in a Bunsen flame? A

B C D Copper(II) sulphate Potassium chloride Barium chloride Lithium sulphate

D Proton nuclear spectroscopy

8. Which of the following represents a valid Lewis electron dot diagram for ozone, O3? A

O O O

4. Which of the following indicators transmits only the lower frequencies of the visible spectrum at low pH? Indicator A

B C D Colour in acid Violet Green Yellow Red Colour in alkali

Red Blue Violet Yellow

O O
C

O O O

5. When electrons occupy degenerate orbitals, they do so in such a way as to maximise the number of parallel spins. This statement is known as A

B C D the Pauli exclusion principle Heisenberg’s uncertainty principle the aufbau principle Hund’s rule.

O O O

[Turn over [X012/13/02] Page three

9. Which of the following substances contains a dative covalent bond? A NH3 B NCl3 C NH4Cl D

CH3NH2

12.

Electrical conductivity

10. Which of the following molecules has the greatest number of non-bonding electron pairs (lone pairs)? A

Temperature The graph shows how the electrical conductivity varies with temperature in A a metal an ionic solid a semiconductor a superconductor.

H H C H H C H Cl O

B C D

B C

H H C H N

13. Which of the following compounds contains hydride ions? A NH3

B HCl C H2S D CaH2

H H C H O H

11. The following diagram square-planar structure.

represents

14. In which of the following reactions does the oxidation state of copper neither increase nor decrease? A Zn + CuSO4 ? ZnSO4 + Cu B

CuSO4 + 4NH3 ? [Cu(NH3)4]SO4 C FeCl2 + CuCl2 ? FeCl3 + CuCl

Where and bonding electron pairs

represent

Cu + 4HNO3 ? Cu(NO3)2 + 2H2O + 2NO2

and represents a non-bonding electron pair (lone pair). Which of the following species could have the structure shown above? A SF4

B NH4
+

15. 100 cm3 of 0·500 mol l–1 AgNO3(aq) is reacted with excess CaCl2(aq). What mass of precipitate forms? A B

C D 7·17 g 8·95 g 12·6 g 14·3 g

C XeF4 D AlH4
–

[X012/13/02]

Page four

16. When a salt, formula Ni(H2O)6.K2(SO4)2, is dissolved in water, the solution contains the ions Ni(H2O)62+, K+ and SO42–. The total number of moles of ions in one

litre of 0·01 mol l–1 solution is A 0·01 B 0·03 C 0·05 D 0·10.

20. Substance X is distributed between equal volumes of two immiscible liquids as shown in the diagram. The number of dots represents the relative distribution of X in the two

liquids at equilibrium.

hexane water

–1 potassium sulphate 17. What volume of 0·2 mol l? is required to make, by dilution with water, one litre of a solution with a potassium ion –1 concentration of 0·1 mol l? ?

X(aq)

X(hexane)

The partition coefficient for this system is A 0·46 B 0·50 C 2·00 D 2·17.

A B C D

100 cm3 250 cm3 400 cm3 500 cm3

18. Phosphoric acid is a weak acid and undergoes partial dissociation according to the equation H3PO4 H2PO4– + H+

21. Which of the following decreases when an aqueous solution of ethanoic acid is diluted? A pH B [H+] C pKa

D The degree of dissociation

The position of equilibrium would be shifted to the right by the addition of A B C

D a catalyst sulphuric acid sodium hydroxide sodium dihydrogenphosphate.

22. Iodide ions are oxidised by acidified nitrite ions according to the equation 2NO2– + 2I– + 4H+ ? 2NO + I2 + 2H2O Addition of sodium ethanoate to

the reaction mixture slows down the formation of iodine. The most likely explanation for this effect is that ethanoate ions A B

C D remove iodine reduce the concentration of iodide ions react with nitrite ions react with hydrogen ions.

19. Caffeine can be extracted dissolved in water using dichloromethane (CH2Cl2). caffeine(aq)

from coffee the solvent

caffeine(CH2Cl2)

Which of the following, when increased, will change the value of the partition coefficient for this equilibrium? A Temperature B

C D Mass of coffee Volume of water Volume of dichloromethane

[Turn over

[X012/13/02]

Page five

23. Which of the following indicators should be used in the titration of potassium hydroxide solution with ethanoic acid solution? A B

C D Phenolphthalein, pH range 8·0 – 9·8 Bromothymol blue, pH range 6·0 – 7·6 Methyl red, pH range 4·2 – 6·2 Methyl orange, pH range 3·1 – 4·4

25. The element X can exist in two forms, as X=X, or as X8 with the following cubic structure. X X

X
24. The following diagram illustrates the catalysed and uncatalysed reaction pathways for a reversible reaction.

X X

Energy Reactants r

The X—X bond dissociation enthalpy is 163 kJ mol–1. The X=X bond dissociation enthalpy is 944 kJ mol–1. Which of the following is the value of DH, in

kJ mol–1, for the reaction X8(g) ? 4X2(g)?

q Products Reaction pathway A –2472 B –1820 C +1820 reverse D +2472

The activation energy for the uncatalysed reaction is given by A B C D s–r p+s

q–p p + r.

26. Which of the following sets of information would enable the bond enthalpy of a C=C double bond to be calculated?

A B C D Enthalpy of formation of ethene benzene

Enthalpy of combustion of Enthalpy of sublimation of (Mean) bond enthalpy of C—H, H—H C—H, H—H carbon carbon C—H, H—H C—H, H—H

ethene benzene

[X012/13/02]

Page six

27. In which of the following changes will there be an increase in entropy? A CO2(g) ? CO2(s) B C

D Combustion of ethanol Hydrogenation of ethene Phenylethene ? poly(phenylethene)

31. Bromine reacts with propene to produce 1,2-dibromopropane. A possible intermediate in the reaction is

H
A H

Br C H Br C H C H Br C H Br C H C H H C H H H C H H

C H H

28. One mole of which of the following chlorides would have the greatest entropy at 750 °C? A B C

D Sodium chloride Calcium chloride Potassium chloride Magnesium chloride

B H

C H H

C H

29. The conversion of butanoic acid into butan-1-ol is an example of A elimination B substitution C oxidation

D reduction. D H

H C H

32. Which of the following represents an initiation step in a chain reaction? 30. propan-1-ol A Cl2 ? 2Cl• B CH3• + CH3• ?

C2H6 C CH4 + Cl• ? CH3Cl + H• D CH3• + Cl2 ? CH3Cl + Cl•

?
1-chloropropane

?
propene

?
methoxypropane

33. Which of the following compounds would be expected to have the highest boiling point? A Pentanal B Pentan-2-ol

C Pentan-2-one D Ethoxypropane

Which line in the table is correct for the types of reaction taking place at ? , ? and ?? Reaction ? A B C D substitution substitution addition addition Reaction

? elimination reduction reduction elimination Reaction ? substitution substitution condensation substitution

[Turn over

[X012/13/02]

Page seven

34. Which line in the table shows a general formula which does not match the homologous series? General formula A B C D CnH2nO CnH2nO2 CnH2n+2O CnH2nO Homologous series

alkanals alkanoic acids alkanols ethers

37. Phenylamine reacts with hydrochloric acid.

H + HCl

The products are A H

Cl + H2

35. The Williamson synthesis for the preparation of unsymmetrical ethers (ROR’) starting with an alcohol and a halogenoalkane is summarised in the general equations:

Step 1: ROH + Na ? RO Na + ½H2 Step 2: RO–Na+ + R’?X ? ROR’ + Na+X– Using propan-2-ol and 2-chlorobutane, the unsymmetrical ether formed would be

A CH3CH2CH2OCH(CH3)CH2CH3 B CH3CH2CH2OCH2CH2CH2CH3 C CH3CH(CH3)OCH2CH2CH2CH3 D CH3CH(CH3)OCH

(CH3)CH2CH3
– +

Cl + NH3

C H

H + ½H2

Cl
36. Which of the following is the strongest base? A CH3CH2OH D

H H N+ H _ + Cl

C CH3CH2NH2 D NH2

38. HNO3 H2SO4

NO2

Which species initially attacks the benzene molecule in the above reaction? A NO3– B NO2+ C HSO4–

D NO2

[X012/13/02]

Page eight

39.

The above reaction is an example of A addition B oxidation C elimination D

substitution.

40. Most medicines work by binding to receptors. Receptors are usually A nucleophiles B electrophiles

C D free radicals protein molecules.

[END OF SECTION A]

Candidates are reminded that the answer sheet for Section A MUST be placed INSIDE the front cover of your answer book.

[Turn over for SECTION B on Page ten

[X012/13/02]

Page nine

SECTION B 60 marks are available in this section of the paper. All answers must be written clearly and legibly in ink.

Marks

1. (a) Name a dopant which could be added to germanium to make a p-type semiconductor. (b) What is the charge carrier in a p-type

semiconductor?

1 1 (2)

2. Burning magnesium continues to burn when placed in a gas jar of carbon dioxide according to the equation 2Mg(s) + CO2(g) ? 2MgO(s) + C(s) Substance

Mg(s) CO2(g) burning spoon carbon dioxide gas jar magnesium MgO(s) C(s) S°/JK–1 mol–1 33·0 214 27·0 5·70

(a) Using the values from the table above, calculate DS° for the reaction. (b) Using the information below and your answer to (a), calculate DG° for

the burning of magnesium in carbon dioxide. Mg(s) + ½O2(g) ? MgO(s) DH° = –?493 kJ mol–1

C(s) + O2(g) ? CO2(g) DH° = –394 kJ mol–1

3 (4)

[X012/13/02]

Page ten

Marks 3. The Born-Haber cycle diagram shows the theoretical process involved in the formation of rubidium chloride from the elements rubidium and chlorine. Rb+(g) + e– + Cl(g) DH? 409

kJ DH? Rb+(g) + Cl–(g) Rb(g) + Cl(g) DH? 121·5 kJ

Rb(g) + ½Cl2(g) Rb(s) + ½Cl2(g)

DH? 81 kJ

DH?

DH? –?435 kJ Rb+Cl–(s)

(a) Write the equation which represents the standard enthalpy of formation of rubidium chloride. (b) Use the Data Booklet to find the value for

enthalpy change DH?. (c) What name is given to the enthalpy change represented by DH?? (d) Calculate the value for enthalpy change DH?.

1 1 1 1 (4)

4. In a PPA the manganese content of a steel paper clip is determined by converting the manganese into purple permanganate ions, the concentration of which is measured using

colorimetry. At the start of the activity, a calibration graph has to be drawn. (a) What data must be collected to allow the calibration graph to be

drawn? (b) Which colour of filter or wavelength of light should be used in this procedure? (c) A weighed sample of the paper clip is dissolved in 2 mol l–1

nitric acid in a beaker covered with a watch glass which is placed in a fume cupboard because a toxic gas is produced. Name this toxic gas. 1 1 1

(d) Colorimetry is not used to determine potassium content because potassium ions are not coloured. The concentration of potassium ions in a compound can be

determined using atomic absorption spectroscopy at a wavelength of 405 nm. Calculate the energy, in kJ mol–1, of this radiation. 2 (5)

[X012/13/02]

Absorbance

0 400 450 500 550 600 Wavelength/nm 650 700

The absorption spectrum of a solution of sodium tetrachlorocobaltate(II) is shown above. (a) Predict the most likely colour of the solution.

(b) Write the electronic configuration for a cobalt(II) ion in terms of s, p and d orbitals. (c) Write the formula for the tetrachlorocobaltate(II) ion. 1 1 1 (3)

6. Propanoic acid is a weak acid. Sodium propanoate is a salt which can be formed from it. Both propanoic acid and sodium propanoate can be used as mould inhibitors.

(a) Calculate the pH of 0·10 mol l–1 propanoic acid solution. (b) 0·20 moles of sodium propanoate are added to 100 cm3 of the

0·10 mol l–1 solution of propanoic acid. Calculate the pH of the buffer solution formed. 2 (4) 2

[X012/13/02]

Page twelve

7. (a) Calculate the emf of a Cr(s)|Cr3+(aq)||Fe2+(aq)|Fe(s) cell operating under standard conditions. (b) Calculate the free energy change, DG°, in kJ per mole

of chromium, for this cell reaction. (c) Use the Ellingham diagram below to explain whether zinc or aluminium should be chosen to extract chromium from chromium oxide. 0

–100 –200 –300 –400 –500 DG°/kJ mol O2 –600 –700 –800 –900 –1000 –1100
4

Marks 1 3

2Zn + O2 ? 2ZnO

–1

/3Cr + O2 ? 2/3Cr2O3

/3Al + O2 ? 2/3Al2O3

200 400

600

800 1000 1200 1400 1600 1800 2000 2200 Temperature/°C (5)

8. A kinetics study was carried out on the reaction between a halogenoalkane, C4H9Br, and aqueous sodium hydroxide. C4H9Br

+ NaOH ? C4H9OH + NaBr The following results were obtained.

[C4H9Br]/mol l–1 8·0 × 10–4 1·6 × 10–3 1·6 × 10–3 3·2 × 10–3

[NaOH]/mol l–1 0·10 0·10 0·20 0·40

Initial Rate/mol l–1s–1 0·15 0·30 0·30 0·60

(a) What is the order of reaction with respect to (i) the halogenoalkane (ii) the sodium hydroxide? (b) Write

the rate equation for the reaction. (c) Calculate a value for the rate constant, k, including the appropriate units. (d) There are four structural isomers

of C4H9Br. (i) From the above results, which isomer is most likely to have been used? (ii) Explain your answer to (d)(i). 1 1 (6) 1 1 2

[X012/13/02]

Page fourteen

Marks 9. Nickel(II) ions react quantitatively with dimethylglyoxime (C4H8O2N2) forming a complex which precipitates out as a red solid. The equation for the reaction and the structure

of the complex are shown below. Ni2+ + 2C4H8O2N2 ? Ni(C4H7O2N2)2 + 2H+

O H3C N C

O N C CH3

Ni C H3C N O H
Relative formula mass = 288·7 (a) What is the coordination number of nickel in the complex? 1

C N O CH3

(b) When 0·968 g of an impure sample of nickel(II) sulphate, NiSO4.7H2O, was dissolved in water and reacted with dimethylglyoxime, 0·942 g of the red precipitate was

formed. Calculate the percentage, by mass, of nickel in the impure sample of nickel(II) sulphate. 2 (3)

10. A student devised the following reaction sequence. CH2CH3 CH3CH2Cl/AlCl3 Cl2 CH2CH2Cl KOH(aq) X

KOH in ethanol

CHCH2 Cl2

(a) What type of reaction is taking place in step ?? (b) What experimental condition would be required in step (c) Draw a

structural formula for product X. (d) What type of reaction is taking place in step ?? (e) Draw a structural formula for product Y.

11. Methylamphetamine (also known as “speed”) and caffeine are stimulants. A “designer drug” with a structure related to methylamphetamine is ecstasy. Ecstasy

tablets are sometimes contaminated with a substance called 4-MTA. O H CH2 CH CH3 methylamphetamine H O H2C O ecstasy (a) Caffeine contains more than one “amide”

functional group. Draw the structure of caffeine and circle one of the “amide” functional groups. 1 1 CH2 CH CH3 N CH3 H3C S 4-MTA CH2 CH CH3 N CH3 CH3 N N CH3 caffeine H

N H CH3 N N

(b) Which of the four molecules contains a primary amine functional group? (c) Draw the structure of the pharmacaphore common to

methylamphetamine, ecstasy and 4-MTA.

1 (3)

12. In a PPA, cyclohexene is prepared from cyclohexanol using a dehydrating agent. (a) Which dehydrating agent is used in the PPA? (b) (i)

When the reactants have been heated gently for about 15 to 20 minutes, the mixture is allowed to cool. Separation of the product is carried out by adding saturated sodium chloride solution to

the reaction mixture and vigorously shaking them together for about a minute and allowing them to settle and form two layers. 1 1 1

Why is saturated sodium chloride solution used rather than water? (ii) Which piece of apparatus is used in this part of the procedure?

(c) The identity of the product can be verified by using infra-red spectroscopy. Predict one difference that would be observed between the infra-red spectra of

cyclohexene and cyclohexanol.

The diagram below shows a reaction sequence starting from compound A which is pentan-2-ol (C5H12O). C5H12O A H+(aq)/MnO4–(aq) C5H10O D HCN C6H11NO E

Concentrated H2SO4

H+(aq)

B+C (C5H10)

F (C6H12O3)

Compound B can exist as two geometric isomers. Compound C is pent-1-ene. Compound D is the oxidation product of compound A. (a)

Name and draw the structural formulae for the two geometric isomers of compound B. (b) Name compound D. (c) Compound E is a cyanohydrin.

(i) Name the type of reaction occurring when D is converted into E. (ii) Draw a structural formula for compound E. (d) Name or draw a structural formula

for compound F. 1 1 1 (6) 2 1

g of 14. 5·00 g of an organic compound A was burned completely producing 11·89 g of CO2 and 6·08 H2O as the only products. (a) Using the information above,

calculate the empirical formula for compound A. (b) The infra-red spectrum of compound A is shown below. 100 80 60 Transmittance/% 40 3

4000

3500

3000

2500 2000 Wavenumber/cm–1

1500

1000

500

Which bond is responsible for the peak at 1140 cm–1?

1 1

(c) The mass spectrum of compound A shows the molecular ion to have a mass/charge ratio of 74. Deduce the molecular formula of compound A. (d)

The proton nmr spectrum of compound A is shown below.

Relative intensity

Chemical shift, d/ppm Using all the above information, deduce the structural formula for compound A. 1 (6)

Expert paper writers are just a few clicks away

Place an order in 3 easy steps. Takes less than 5 mins.

fractional distillation

Expert paper writers are just a few clicks away

Calculate the price of your order