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24Salters Advanced Chemistry, Pearson Education Ltd 2009. © University of York.
This document may have been altered from the original.
WM End of module test
What’s in a Medicine? end of module test 60 marks (1 hour)A copy of the Data Sheets is required for this test.
1 An ester D is used in food flavourings. The formula of D is CH3COOCH3.
a Draw the full structural formula and give the systematic name for ester D. [2]
b Ester D can be made in the laboratory by the reaction of ethanoyl chloride with alcohol E. i Give the full structural formula of ethanoyl chloride. [1] ii Suggest the name of the alcohol E that reacts with ethanoyl chloride to make ester D. [1]
c Ester D can also be made by reacting alcohol E with carboxylic acid F, CH3COOH. The reaction is carried out by heating under reflux.
i Give the systematic name of carboxylic acid F. [1] ii Name the other reagent that would be needed to obtain a reasonable yield of ester D by this method. [1] iii Explain what is meant by heating under reflux and give one reason why it is necessary in this reaction. [3]
d Carboxylic acid F, CH3COOH, can be made by the oxidation of another alcohol, G. i Give the formula of alcohol G. [1] ii Give the reagents and conditions necessary to convert alcohol G into carboxylic acid F. [3] iii Classify alcohol G as a primary, secondary or tertiary alcohol. Explain your answer. [2] iv Give the conditions necessary to convert alcohol G into an aldehyde H. [2] v Give the systematic name of aldehyde H and draw its full structural formula. [2] vi Aldehyde H reacts with hydrogen cyanide. Give the structure of the compound formed. [1] [TOTAL: 20 MARKS]
2 Cannabis resin contains compounds called cannabinoids. Two compounds contained in fresh cannabis resin are shown below.
HO
COOH
C5H11
O
H3C CH3
H3C
HO C5H11
O
H3C CH3
H3C
BA
a Describe, using diagrams, how you would carry out thin-layer chromatography to demonstrate that cannabis resin contains a mixture of compounds. [5]
b Samples of compounds A and B are isolated from the resin and purified. Various chemical tests are carried out on the compounds.
i Both compounds A and B contain an –OH group attached to a benzene ring. Give the name of this functional group. [1] ii Describe a test (with the expected result) that would show the presence of this functional group. [2]
c Compound B will react with aqueous sodium hydroxide. i Give the formula of the functional group in compound B that causes this reaction. [1] ii What would be observed if compound B were added to aqueous sodium carbonate? Explain your answer. [2]
d Compound A contains a carboxylic acid group, –COOH. i Write the equation for the reaction of the carboxylic acid group with a hydroxide ion. [1] ii Use your equation to explain why the hydroxide ion can be described as a base. [1]
e Compounds A and B have different relative molecular masses. i Give the name of the spectroscopic technique that could be used to show this. [1] ii Explain how the spectra of the two compounds would be used to show this difference. [1]
f Compound A contains a C=O bond. i Give the name of the spectroscopic technique that could be used to show the presence of a C=O bond in compound A. [1] ii Explain how the spectrum would show the presence of a C=O bond. [1] iii What happens to the C=O bond when it absorbs infrared radiation? [2] [TOTAL: 19 MARKS]
25Salters Advanced Chemistry, Pearson Education Ltd 2009. © University of York. This document may have been altered from the original.
End of module test WM
3 In 1936 the compound pethidine, a powerful painkiller, was synthesised by chance. The general structure of pethidine is shown below.
pethidine
�
���
���� C
O
C�H�O
a Two peaks in the mass spectrum of pethidine occur at masses of 15 and 77. Suggest the formulae of the ions giving rise to these two peaks. [3]
b When pethidine is hydrolysed with aqueous acid, ethanol is formed. i The infrared spectrum of ethanol is given below. Explain how it shows the presence of an alcohol. [2] ii What feature of the infrared spectrum would be used to confirm that the spectrum is specifically that of ethanol? [1]
4600 3800 3000 2200 1800 1400 1000 800 600 400
Tran
smitt
ance
(%)
100
80
60
40
20
Wavenumber/cm 1
The infrared absorption spectrum of ethanol.
c When pethidine was first discovered, clinical trials were carried out on the medicine. Give three questions that these trials would answer about the potential of pethidine as a medicine. [3]
d Having discovered a medicine which is effective, scientists then prepare a large number of related compounds. i Explain why they do this. [1] ii Name the technique that scientists use to prepare large numbers of related compounds. Explain how the use of this
technique helps the development of new medicines. [2]
e Esters like pethidine can be synthesised by the reactions of carboxylic acids with alcohols. For example:
2H5OH � 2H5 + H2O i Calculate the atom economy ii Explain the importance of seeking methods of making medicines that have high atom economies. [1]
f Some types of reaction are listed below: addition condensation elimination i Which one of these terms describes the reaction in part e? [1] ii Which one of these types of reaction has the highest atom economy? Explain why. [2] iii Write the equation for an elimination reaction of ethanol. Name the organic product of the reaction. [2] [TOTAL: 21 MARKS]