Unit 2 – Mass Spec & IR
Unit 2 - Jan 2009
Q1.
How many of the following molecules will absorb IR radiation?

   A     Two
   B     Three
   C     Four
   D     Five
(Total for question = 1 mark)

Q2.
Molecules absorb IR radiation because
   A     they change their polarity when they vibrate.
   B     they change their velocity when they vibrate.
   C     they change their magnetic field when they vibrate.
   D     they change their direction of rotation when they vibrate.
(Total for question = 1 mark)

Q3.
Infrared (IR) spectra can be used to follow the progress of reactions involving propan-1-ol and propan-2-ol.  Some absorption ranges by chemical bonds in the IR spectrum are given below.
1     O—H stretching in alcohols at 3750 − 3200 cm−1
2     CO stretching in aldehydes at 1740 − 1720 cm−1
3     CO stretching in ketones at 1700 − 1680 cm−1
4     CO stretching in carboxylic acids at 1725 − 1700 cm−1

(a) To identify the formation of the product when propan-1-ol has been partially oxidized, you can look for absorptions in the IR spectrum at absorption range
(1)
   A     1
   B     2
   C     3
   D     4

(b) To monitor whether all of the sample of propan-2-ol has been oxidized, you can look for
(1)
   A     a lack of absorptions in the IR spectrum at 1.
   B     a lack of absorptions in the IR spectrum at 2.
   C     absorptions in the IR spectrum at 3.
   D     absorptions in the IR spectrum at 4.
(Total for question = 2 marks)

Unit 2 - Jun 2009
Q4.
The infrared spectrum below is most likely to be that of a member of which homologous series?

   A     Alcohol
   B     Chloroalkane
   C     Aldehyde
   D     Carboxylic acid
(Total for question = 1 mark)

Q5.
Which of the following values for the mass/charge ratio for singly charged ions would be present in the mass spectrum of propanal, CH3CH2CHO, but not of propanone, CH3COCH3?
   A     15
   B     29
   C     43
   D     58
(Total for question = 1 mark)

Unit 2 - Jan 2010
Q6.
Butan-1-ol and three other alcohols, X, Y and Z, are isomers.
(a)  (i)  Give TWO observations you would make when any one of the alcohols reacts with sodium.
(2)
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(ii)  Give the molecular formula of the organic product of the reaction.
(1)
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(b)  Isomer X does not react with a mixture of potassium dichromate(VI) and sulfuric acid.
Draw the displayed formula of X and name it.
(2)

Name
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(c)  When isomer Y is heated under reflux with a mixture of potassium dichromate(VI) and sulfuric acid, it forms 2-methylpropanoic acid.
Deduce the structural formula of the alcohol Y.
(1)

(d)  (i)  Isomer Z reacts with a mixture of potassium dichromate(VI) and sulfuric acid to form a compound Q, which does not react with Fehling's or Benedict's solution.
Deduce the structural formula of the alcohol Z.
(1)

(ii)  What would be the principal difference between the infrared spectrum of Q and the infrared spectrum of 2-methylpropanoic acid?
You are not expected to quote absorption values.
(1)
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(e)  One of the isomers, X, Y or Z can be converted to 2-chlorobutane.
What reagent would you use to carry out this conversion?
(1)
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(f)  (i)  2-chlorobutane reacts with silver nitrate in a mixture of ethanol and water as a solvent. What would you see when the reaction occurred?
(1)
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*(ii)  Both ethanol and water contain hydrogen bonds. By considering the hydrogen bonding on these two solvents, suggest why 2-chlorobutane is more soluble in ethanol than in water.
(2)
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 (Total for question = 12 marks)

Unit 2 - Jun 2010
Q7.
This question is about the chemistry of some halogenoalkanes.
Halothane is a colourless and sweet-smelling liquid. It has a boiling temperature of 50°C. Halothane vapour was used as a general anaesthetic in hospitals during the mid to late 20th Century. Patients inhaled the halothane vapour under medical supervision. However, halothane was found to have some adverse side-effects and was therefore replaced by other halogenoalkane anaesthetics.
Halothane has the structure

In an experiment, halothane was heated in a test tube with aqueous silver nitrate and ethanol, using a water bath. Compound X and bromide ions were formed. The structure of compound X is shown below.

(a)  (i)  Give the systematic name of halothane.
(1)
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(ii)  Suggest the types of intermolecular force present between molecules of liquid halothane.
(2)
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(iii)  In the above experiment, suggest ONE reason why a water bath was used rather than heating the test tube containing the reaction mixture directly over a Bunsen flame.
(1)
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(iv)  Suggest why ethanol was used in this experiment.
(1)
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(v)  What would be seen in the test tube as the reaction progressed?
(1)
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 (vi)  Write an ionic equation to show the reaction between aqueous silver ions and aqueous bromide ions. Include state symbols in your equation.
(1)

(b)  Chloroethane, C2H5Cl, can also be used as an anaesthetic. In an experiment, chloroethane was hydrolysed by aqueous sodium hydroxide, NaOH.
(i)  Name, and give the structural formula of, the organic product of the hydrolysis of chloroethane.
(2)
Name
 ............................................................................................................................................. 
Structural formula
 ............................................................................................................................................. 
(ii)  The hydrolysis of chloroethane is an exothermic reaction which takes place in a single step.
On the diagram below, draw the energy profile for the reaction. Label clearly the activation energy for the reaction.
(3)

(c)  In the early 1900s, the CFC with formula CCl2F2, was identified as a refrigerant which was both non-flammable and non-toxic.
(i)  What does the term CFC stand for?
(1)
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(ii)  Suggest ONE use for CFCs other than as a refrigerant.
(1)
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*(iii)  In the stratosphere, CFCs are broken down by absorption of UV radiation to form chlorine free radicals.
The following two reactions occur.

Combine these two equations to give the overall equation for the reaction of ozone in the stratosphere. State the role played by the chlorine free radical in the overall reaction. Hence explain why many scientists consider the effect of CFCs on ozone to be harmful.
(5)

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(d)  The compound of formula CH2F2 has replaced several CFCs for commercial use. If molecules of CH2F2 reach the stratosphere, they do not break down to produce fluorine free radicals.
(i)  Suggest why C-F bonds are not broken in the stratosphere.
(1)
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*(ii)  The compound CH2F2 acts as a greenhouse gas when it absorbs a particular type of radiation.
Name the type of radiation and explain why a molecule of CH2F2 is able to absorb this radiation.
(2)
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(Total for question = 22 marks)

Q8.
Which of the following features is shown by the mass spectra of propanone and propanal?

(Total for question = 1 mark)

Unit 2 - Jan 2011
Q9.
 Which of the following is a greenhouse gas?
   A      Argon
   B      Nitrogen
   C      Oxygen
   D      Water vapour
(Total for question = 1 mark)

Q10.
Consider the following organic liquids:
A  ethanal
B  ethanol
C  tetrachloromethane
D  trichloromethane
(a) Each liquid is run from a burette. Which liquid would not be deflected significantly by a charged rod?
(1)
   A
   B
   C
   D

(b) Which liquid would react with phosphorus(V) chloride to give a gas which fumes in moist air?
(1)
   A
   B
   C
   D

(c) Which liquid would you expect to have the peak at the greatest mass/charge ratio in its mass spectrum?
(1)
   A
   B
   C
   D

(d) Which liquid has an infrared spectrum with a broad absorption due to hydrogen bonding?
(1)
   A
   B
   C
   D
(Total for question = 4 marks)

Unit 2 - Jun 2011
Q11.
There would be a major peak in the mass spectrum for butan-1-ol, CH3CH2CH2CH2OH, but not for butan-2-ol, CH3CH2CH(OH)CH3, at m/e value
   A    15
   B    17
   C    29
   D    43
(Total for Question = 1 mark)

Q12.
This question is about nitrogen monoxide, NO, which can be described both as a friend and a foe.

(a) (i)   What is meant by the term free radical?
(1)
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(a) (ii)  Suggest a dot and cross diagram for nitrogen monoxide, showing outer shell electrons only, remembering that it is a free radical.
(2)

(b) (i)   Part of the unbalanced equation for the preparation of nitrogen monoxide from nitric acid is shown below.

Identify the elements which are oxidized and reduced and give their oxidation numbers.
(3)
Element oxidized .........................
Oxidation number initial .........................    final .........................

Element reduced .........................
Oxidation number initial .........................    final .........................
    
 (ii)  Complete and balance the equation for the reaction between silver and nitric acid.
(2)

(c) The reaction between nitrogen and oxygen to form nitrogen monoxide reaches equilibrium.

     (i)   Explain why the yield of nitrogen monoxide is increased when the temperature is increased.
(1)
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  ∗(ii)  State and explain the effect, if any, on the yield of nitrogen monoxide when the pressure is increased.
(2)
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   (iii)  State and explain how the rate of the reaction is affected by an increase in pressure.
(2)
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∗ (d) (i)  Explain why a jet aeroplane in flight causes much more damage to the ozone layer than cars carrying the same number of passengers at sea level. You should assume that the nitrogen monoxide outputs for both methods of conveying the passengers are the same.
(2)
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   (ii)  The reactions of chlorine free radicals with ozone may be represented by the following equations.

Write corresponding equations for the reactions of the free radical nitrogen monoxide with ozone. Combine your two equations to show the overall reaction.
Use these equations to explain why a small quantity of nitrogen monoxide can have a continuing effect on the ozone layer.
(5)
Equations

Explanation
      ..............................................................................................................................................
      ..............................................................................................................................................
      ..............................................................................................................................................
(Total for Question = 20 marks)

Q13.
The enthalpy change of neutralization of an acid by an alkali is measured by adding 10.0 cm3 of hydrochloric acid to 10.0 cm3 of sodium hydroxide. 10.0 cm3 pipettes with an accuracy of ±0.04 cm3 are used to measure out both solutions.
The overall percentage error in measuring the total volume of the reaction mixture is
   A    ±0.04%
   B    ±0.08%
   C    ±0.4%
   D    ±4.0%
(Total for Question = 1 mark)

Q14.
Methanol dissolves in water mainly due to the formation of new
   A    hydrogen bonds.
   B    dipole-dipole forces.
   C    London forces.
   D    covalent bonds.
(Total for Question = 1 mark)

Unit 2 - Jan 2012
Q15.
When propanal, CH3CH2CHO, and propanone, CH3COCH3, are compared using physical methods of analysis, which of the following is not correct?
   A  The carbonyl groups absorb at very similar frequencies of the IR spectrum.
   B  The compounds will have different patterns in the fingerprint region of the IR spectrum. 
   C  The compounds will form different fragmentation patterns in a mass spectrum. 
   D  The compounds will have molecular ion peaks at different mass to charge ratios in a mass spectrum.
(Total for question = 1 mark)

Unit 2 - Jun 2012
Q16.
These questions concern the use of infrared (IR) spectra to identify organic compounds. The IR absorption ranges associated with some organic functional groups are given below.
   A       O—H stretching in alcohols at 3750 − 3200 cm−1
   B       CO stretching in aldehydes at 1740 − 1720 cm−1
   C       CO stretching in ketones at 1700 − 1680 cm−1
   D       CO stretching in carboxylic acids at 1725 − 1700 cm−1

      (a) When propan−2−ol is refluxed with potassium dichromate(VI) and sulfuric acid, the product will show a peak due to
(1)
   A
   B
   C
   D
      (b) When propan−1−ol is heated with potassium dichromate(VI) and sulfuric acid, the product, that is distilled off as it is formed, will show a peak due to 
(1)
   A
   B
   C
   D
(Total for question = 2 marks)

Q17.
 Fuels of the Future
 Concerns about the future availability of fossil fuels, and the fact that their combustion produces greenhouse gases, have led to a search for alternative sources of energy. A great deal of attention has been directed at developing the use of hydrogen as a fuel. Since the only product of its combustion is water, hydrogen is considered to be a clean fuel.
However, the use of hydrogen has major drawbacks. The small size of the hydrogen molecule means that it is difficult to prevent leaks and, to store enough to provide a reasonable amount of fuel for a car, hydrogen must be compressed to around 700 atmospheres. Furthermore, the main source of hydrogen is currently fossil fuels such as methane, which is combined with steam in a series of reactions to form carbon dioxide and hydrogen.
One suggested alternative to hydrogen is ammonia. Ammonia, which is obtained by combining nitrogen and hydrogen at temperatures around 450°C and pressures of about 150 atmospheres, also has serious disadvantages: it is a toxic, corrosive and pungent gas which is difficult to ignite.
However, burning ammonia produces only nitrogen and water and it is relatively easy to liquefy, having a boiling temperature of just −33°C. Furthermore, the technology works: ammonia was used as a fuel for Belgian buses in the Second World War and, in 2007, the 'NH3 Car' project based in Ann Arbor, Michigan, used a mixture of ammonia and petrol to fuel a 2500 mile journey, from Detroit to San Francisco, in a modified pickup truck.
(a)  (i)  Explain the term greenhouse gas.
(2)
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*(ii) State and explain whether or not water (in the gaseous state) is a greenhouse gas.
(2)
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(iii) Write the equation for the formation of hydrogen from methane and steam. State symbols are not required.
(2)

(iv) Suggest why using methane to form hydrogen in this way is preferable to burning methane directly.
(1)
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 (v) Storing hydrogen at a pressure of 700 atmospheres is a disadvantage to its use as a fuel because of the costs involved. Suggest why using such high pressures is so expensive.
(1)
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 (b)  (i)  Draw a dot and cross diagram for ammonia, showing the outer electrons only.
(1)

*(ii) By considering the intermolecular forces involved, explain why methane has a boiling temperature of 109 K while ammonia has a boiling temperature of 240 K, although these two compounds have very similar molar masses.
(4)
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 (c)  (i)  Write the equation for the combustion of ammonia. State symbols are not required.
(2)

(ii) The enthalpy change of combustion of methane is −890.3 kJ mol−1 and that of ammonia is −510.1 kJ mol−1. Suggest two additional items of information, not connected with environmental factors or the fact that methane is non-renewable, which would be useful in comparing methane and ammonia as fuels.
(2)
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 (iii) The fact that ammonia has a pungent smell is listed as a disadvantage of its use as a fuel. Suggest why this might also be an advantage.
(1)
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 (iv) Suggest why ammonia was mixed with petrol in the 'NH3 Car' project.
(1)
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 (v) State, with a reason, whether hydrogen or ammonia can currently be considered to be long term replacements for fossil fuels.
(1)
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 (Total for question = 20 marks)

Unit 2 - Jun 2013
Q18.
(a)  Sea water is a source of chemicals. The most abundant chemical dissolved in sea water is sodium chloride. Compounds of magnesium and bromine are also present. Magnesium occurs at 1300 parts per million (ppm) and bromine at 60 ppm by mass.

The solution left after crystallizing sodium chloride from sea water is even richer in bromine, and contains around 2.2 g dm−3 of bromine.

Bromine is extracted from this solution by passing in chlorine gas. The mixture is acidified to prevent hydrolysis of bromine by the reaction
Br2(aq) + H2O(l)  2H+(aq) + Br−(aq) + BrO−(aq)

The bromine can be separated by heating the solution to collect bromine vapour which is then condensed, or by blowing air through the solution.

(i)  Show by calculation that a solution containing 2.2 g dm−3 of bromine is richer in bromine than one containing 60 ppm.

[Assume that the mass of 1 dm3 of the bromine solution is 1000 g]
(1)

(ii)  Write an ionic equation, including state symbols, for the reaction in which chlorine gas reacts with bromide ions in solution to produce bromine.
(2)

(iii)  What would be observed when the reaction in (ii) occurs?
(1)
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(iv)  Explain why the addition of an acid, such as hydrochloric acid, prevents hydrolysis of bromine.
(2)
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(v)  Assuming the hydrolysis of bromine is endothermic, explain how an increase in temperature would affect the equilibrium position for the hydrolysis of bromine.
(2)
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(vi)  Use your knowledge of activation energy to explain why an increase in temperature increases the rate of hydrolysis of bromine.
(1)
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(vii) Use the equation for the hydrolysis of bromine to show that it is a disproportionation reaction.
Br2(aq) + H2O(l)  2H+(aq) + Br−(aq) + BrO−(aq)
(2)
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(b) At the surface of the sea, there is a dynamic equilibrium between carbon dioxide gas in air and dissolved carbon dioxide in the surface sea water.
CO2(g) CO2(aq)

(i)  State two features of a system which has reached dynamic equilibrium.
(2)
1.  .................................................................................................................................................... 
    ....................................................................................................................................................
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2.  .................................................................................................................................................... 
    ....................................................................................................................................................
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*(ii)  Carbon dioxide dissolves more easily in seawater than in pure water because seawater contains carbonate ions, CO32−(aq), and the following reaction occurs.
CO2(aq) + H2O(l) + CO32−(aq)  2HCO3 −(aq)

Explain how an increase in concentration of carbonate ions in sea water affects the amount of carbon dioxide gas in the atmosphere.
(2)
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(iii)  Carbon dioxide and water vapour both contain polar bonds.
What effect does infrared radiation have on the bonds in these molecules?
(1)
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*(iv)  Outline the mechanism by which molecules such as carbon dioxide and water cause global warming.
(2)
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*(v) Without water vapour in the atmosphere, the earth would be many degrees colder than it is at present. Why are many climate change scientists more concerned about warming due to carbon dioxide in the atmosphere, than warming due to the presence of water vapour? Refer to the difference between anthropogenic climate change and natural climate change in your answer.
(4)
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(Total for Question = 22 marks)

Q19.
Which type of radiation is absorbed by molecules and results in the greenhouse effect?
   A    Infrared
   B    Microwave
   C    Ultraviolet
   D    X-ray
(Total for Question = 1 mark)

Q20.
Which of the following is not a greenhouse gas?
   A    H2O
   B    NO
   C    CH4
   D    O2
(Total for Question = 1 mark)

Q21.
(a)  The products of the reaction when 2-chlorobutane is heated with sodium hydroxide depend on the conditions.
(i)  What condition, other than a suitable temperature and sodium hydroxide concentration, would produce a mixture of but-1-ene and but-2-ene?
(1)
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(ii)  What type of reaction occurs in (a)(i)?
(1)
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(iii)  What condition, other than a suitable temperature and sodium hydroxide concentration, would produce butan-2-ol in the reaction of 2-chlorobutane with sodium hydroxide?
(1)
 ............................................................................................................................................. 

(iv)  Suggest the mechanism for the reaction of 2-chlorobutane with hydroxide ions to form butan-2-ol. Use curly arrows to show the movement of electron pairs.
(2)

(b)  Phosphorus(V) chloride, PCl5, can be used to test for the –OH group.

Describe what would be seen when phosphorus(V) chloride is added to butan-2-ol. Give the equation for the reaction. State symbols are not required.
(2)
Observation
 ............................................................................................................................................. 
Equation

(c)  A tertiary alcohol, A, is an isomer of butan-2-ol.
(i)  Butan-2-ol and A can be distinguished by warming separate samples with a mixture of potassium dichromate(VI) and sulfuric acid. State the observations which would be made with each alcohol.
(2)
Observation with butan-2-ol
 ............................................................................................................................................. 

Observation with A
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(ii) Give the structural formula of the organic product which forms when butan-2-ol is oxidized.
(1)

(iii)  Explain how infrared spectroscopy could be used to detect whether butan-2-ol has been oxidized.
(1)
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(Total for Question = 11 marks)

Q22.
A compound which has major peaks with mass / charge ratio at 29, 57 and 58 in the mass spectrum could be
   A    propanal, CH3CH2CHO.
   B    propanone, CH3COCH3.
   C    propan-1-ol, CH3CH2CH2OH.
   D    propan-2-ol, CH3CH(OH)CH3.
(Total for Question = 1 mark)

Q23.
The molecular (parent) ion in the mass spectrum of a hydrocarbon containing 12C and 1H only
   A    is the peak with highest relative abundance.
   B    is the peak with highest charge.
   C    is the peak produced by the most stable fragment.
   D    is the peak with highest mass to charge ratio.
(Total for Question = 1 mark)

Q24.
Ethane-1,2-diol, CH2OHCH2OH, is commonly used in antifreeze for cars to lower the freezing temperature of the water in the car radiator. It reacts in a similar way to ethanol but both of the alcohol groups can react.
(a)  Write an equation for the complete reaction between sodium and ethane-1,2-diol. State symbols are not required.
(2)

(b)  Ethane-1,2-diol is very quickly oxidized to ethanedioic acid, (COOH)2, even under the conditions shown below.

However, ethanol requires stronger oxidizing conditions to be converted into ethanoic acid.
Explain how you would change the above apparatus to achieve this oxidation of ethanol.
(2)
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(c)  Draw the skeletal formula of ethanedioic acid.
(1)

(d)  Explain why phosphorus(V) chloride, PCl5, would not be a suitable reagent to be used to distinguish between ethane-1,2-diol and ethanedioic acid.
(1)
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(e)  (i)  Depending on the reaction conditions, ethanol can be oxidized to either an aldehyde or to carboxylic acid. Infrared spectroscopy is a suitable technique for determining whether the oxidation product obtained is an aldehyde or a carboxylic acid.
Draw, on the spectrum below, any peak(s) that you would expect to see between 4000 and 1500 cm−1 if the product was an aldehyde and not a carboxylic acid.
(2)
DATA
The IR absorption ranges associated with some organic functional groups are given below:
O—H stretching in alcohols (variable, broad) at 	3750 − 3200 cm−1 	
O—H stretching in carboxylic acids (weak) at 	3300 − 2500 cm−1 	
CO stretching in aldehydes (strong) at 	1740 − 1720 cm−1 	
CO stretching in ketones (strong) at 	1700 − 1680 cm−1 	
CO stretching in carboxylic acids, alkyl (strong) at 	1725 − 1700 cm−1 	
C—H stretching in aldehydes (weak) at 	2900 − 2820 cm−1 	
                                       and (weak) at 	2775 − 2700 cm−1 	

(ii)  The infrared spectrum of the distillate from the reaction in (e)(i) included a peak at 3750–3200 cm−1.
What substance is likely to have caused this?
(1)
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(iii)  Mass spectrometry can be used to identify the products of the oxidation of ethanol. Suggest the formula of a fragment that would show when ethanoic acid is produced and would not be present in either ethanol or ethanal.
(1)
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(f)  Treatment of 2-bromoethanol, CH2BrCH2OH, with aqueous sodium hydroxide would be one way to produce ethane-1,2-diol.
(i)  Complete a possible mechanism for this reaction in the space below.
(3)

(ii)  Classify the mechanism and type of reaction in (f)(i):
(2)
Mechanism
 ............................................................................................................................................. 
Type
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(g)  Aqueous silver nitrate can be used to test for the presence of bromide ions. Write an ionic equation for the reaction. Include state symbols in your answer.
Ionic Equation
*(h)  It can be difficult to distinguish between the colours of the silver halides. The use of solutions of ammonia can be very helpful.
A silver halide dissolved in concentrated ammonia to form a colourless solution.
Explain why this result does not prove conclusively that the silver halide was silver bromide and give a further test to confirm that the silver halide is silver bromide.

(2)
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(Total for Question = 19 marks)

Unit 2 - Jun 2014
Q25.
 Alkanes are now being used as aerosol propellants as an alternative to CFCs. Although they have no effect on the ozone layer, they have the disadvantage of
   A    having high reactivity.
   B    being hard to evaporate.
   C    being greenhouse gases.
   D    having an unpleasant smell.

  
(Total for question = 1 mark)

Q26.
 Consider the infrared spectrum shown below.

The IR absorption ranges associated with some organic functional groups are given below.

Which of the following could have produced the above spectrum?
   A    An aldehyde
   B    An alcohol
   C    A carboxylic acid
   D    A ketone
(Total for question = 1 mark)

Q27.
 What effect does infrared radiation have on the covalent bonds in water molecules in the atmosphere?
   A    They are broken to form free radicals.
   B    They are broken into ions.
   C    The bonds vibrate more vigorously.
   D    There is no effect on the bonds.
(Total for question = 1 mark)

Q28.
In a mass spectrum of butane, C4H10, where would a peak be seen for the molecular ion if it had a charge of 2+?
   A    29
   B    56
   C    58
   D    60
(Total for question = 1 mark)

Q29.
Insect-borne diseases, such as malaria, affect the lives of millions of people. Chemists are constantly finding new compounds to combat the transmission of these diseases. One such compound is the insect repellent commonly called p-menthane-3,8-diol (this is not its systematic name). It is used to protect both humans and animals.
The structure of p-menthane-3,8-diol is shown below.

p-menthane-3,8-diol is found naturally in the leaves of Eucalyptus citriodora, which is native to Australia and is commonly known as 'Lemon Bush'. It can be extracted from these leaves but is currently commercially prepared by chemical synthetic pathways. However, the commercially-made chemical has been found by some scientists to be less effective than the natural leaf extract.
It is possible that p-menthane-3,8-diol can kill microorganisms and it is this additional potential use and others which are being investigated by the chemical industry.
p-menthane-3,8-diol should not be confused with either methane or methanol.
(a)  p-menthane-3,8-diol has two alcohol functional groups. Classify the type of alcohol group on the far left of the structure drawn above and explain the meaning of the term 'functional group'.
(2)
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(b)  Give the molecular formula of p-menthane-3,8-diol.
(1)
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(c)  p-menthane-3,8-diol is found in the oily extract from the leaves of the 'Lemon Bush'.
One method used to extract the oil is described below.
Initially, the leaves are ground up using a pestle and mortar with some sand and an organic solvent, such as cyclohexane.
(i)  Suggest why sand is used.
(1)
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*(ii)  The solvent cyclohexane forms intermolecular forces with other organic molecules when they dissolve.
Identify these intermolecular forces and explain how they arise.
(3)
Type of intermolecular force
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How they arise
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(iii)  How could the sand and other solid residue be removed from the mixture?
(1)
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(iv)  At this stage, either anhydrous magnesium sulfate or calcium chloride is added. Suggest the reason for this.
(1)
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*(v)  A student suggested using the following apparatus to remove the cyclohexane from the mixture.

Explain, in terms of the processes that occur in the above apparatus, why this method is unsuitable to remove the cyclohexane.
Suggest how this apparatus could be adjusted for a successful separation.
DATA

·	Boiling temperatures: p-menthane-3,8-diol 266 °C; cyclohexane 81 °C(4)
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(d)  Spectroscopic techniques can be used to confirm the presence and identity of organic molecules such as p-menthane-3,8-diol.
(i)  Suggest how infrared spectroscopy could be used to confirm the presence of the functional group in a molecule such as p-menthane-3,8-diol.
(1)
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(ii)  Suggest the identity of two fragment ions, with a m/e value of more than 13 but less than 20, that could be observed in a mass spectrum of p-menthane-3,8-diol.
(2)
First fragment ion
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Second fragment ion
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(e)  One reason why the synthetic p-menthane-3,8-diol may be less effective than the natural extract is because there are many isomers of this molecule.
Complete the structures below to show two structural isomers of p-menthane-3,8-diol which have the same number of alcohol functional groups and the same carbon skeleton.
(2)

*(f)  State two key principles of sustainability, and how the chemical industry might achieve these, when mass-producing a molecule such as p-menthane-3,8-diol.
(4)
Principle 1
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Principle 2
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 (Total for question = 22 marks)