Learning Outcome 1.0
Assessment Criteria:
1.1 Define alkene, alkane and haloalkane
1.2 Name alkenes, alkanes and haloalkanes
1.3
Explain the formation of haloalkanes by free radical substitution
Assignment Brief Assignment to be completed independently by the student. You will need a data sheet or access to a book of data and a periodic table to complete this assignment. Learning Outcome 1.0 Assessment Criteria: 1.1 Define alkene, alkane and haloalkane 1.2 Name alkenes, alkanes and haloalkanes 1.3 Explain the formation of haloalkanes by free radical substitution 1 Classify each of the following as: a) ALKANE, b) ALKENE or c) HALOALKANE. Then name each molecule. i) C8H18 ii) C2H4 iii) CH3CH2CH2Cl iv) v) CH3CH2CHCHCH2CH3 vi) CH3CH2CH2CH2CH2CHBrCH3 vii) C5H12 2 Explain the meaning of the following terms: i) Substitution reaction ii) Free radical Methane and chlorine will react in the presence of ultra violet light to produce chloromethane and hydrochloric acid through a free radical substitution mechanism. iii) Write the equation for this reaction iv) Explain the stages in this process; for each stage give examples of the reactions involved; include the following terms and identify the species that are free radicals: Photochemical reaction; free radical; homolytic bond fission; initiation, propagation, termination. Learning Outcome 2.0 - Understand nomenclature of organic molecules containing oxygen and nitrogen. Assessment Criteria 2.1 – Name organic molecules containing oxygen and nitrogen. Identify the homologous series and systematically name the following molecules: a) b) CH3CH2CH2NH2 c) CH3CH2CHO d) CH3CHOHCH2CH3 e) f) CH3CH2OCH2CH3 g) CH3COCH3 h) i) CH3COCl j) CH3CONH2 k) l) CH3COCH2CH2CH2CH3 Learning Outcome 3.0 Understand reactions of molecules containing oxygen and nitrogen. 3.1 Write equations to show the reactions of molecules containing oxygen and nitrogen. 3.2 Use mechanisms to explain these reactions. 1 Write equations for the following reactions of alcohols . In each case identify the homologous series of the product, name the product and the type of reaction involved. i) Butan-1-ol refluxed with excess acidified potassium dichromate (VI) solution. ii) Ethanol (excess) heated with acidified potassium dichromate (VI) solution, products distilled out as the reaction proceeds. iii) Propan-1-ol refluxed with butanoic acid with a few drops of concentrated sulphuric acid added. iv) Butan-1-ol heated to 300oC over aluminium oxide, Al2O3. v) Pentan-2-ol refluxed with acidified potassium dichromate(VI). 2 Explain and describe the test that you would use to distinguish between primary, secondary and tertiary alcohols. 3 A student wants to confirm that an organic compound is an aldehyde. She decides to use a test with Fehlings solution A and B. i) Describe how she should carry out this test. ii) What observation would identify the compound as an aldehyde? 4 The nucleophilic addition of cyanide ions (CN-) across the carbonyl group on an aldehyde or ketone is useful to chemists because a new C-C bond is formed. i) Draw the mechanism of the reaction between ethanal and hydrogen cyanide. ii) Explain why this mechanism is classified as nucleophilic addition. 5 Write balanced equations for the reactions between: i) Ethanoyl chloride and ethanol ii) Ethanoic anhydride and propan-1-ol. 6 A chemist wants to prepare the ester pentyl ethanoate. i) Name the alcohol needed for this preparation and draw its displayed formula. ii) Give the names of 3 compounds that could be used to react with the alcohol to produce this ester. 7 Draw structures for the products formed when propylamine reacts with: i) Water ii) hydrochloric acid iii) ethanoyl chloride Learning Outcome 4.0 Understand optical isomerism. 4.1 Explain optical isomerism. 1 What structural feature must a molecule possess if it forms optical isomers (enantiomers)? 2 Which of the following molecules can have optical isomers? Explain your answers. i) CH3Cl ii) CH2ClBr iii) CHClBrI 3 i) Draw the structural formula of 2-bromo butane. ii) Use 3D diagrams to show the structures of the two enantiomers of this molecule. iii) Draw the structural formula of the amino acid alanine, (R group =CH3). iv) Identify the chiral carbon with an asterisk v) Use 3D diagrams to show the structures of the two optical isomers of this molecule. vi) Label the isomers D or L and explain what these classifications represent. 4 Define the term ‘racemic mixture’. 5 Enantiomers behave differently in the presence of other chiral molecules. Research the example of thalidomide to explain the significance of understanding the behaviour of different enantiomers, (remember to reference your sources, word count 300). Learning Outcome 5.0 Understand benzene rings. 5.1 Explain benzene and its structure. 1 Describe the bonding in benzene according to the accepted delocalised electron model. 2 Describe the structure for benzene suggested by Kekule in 1865. 3 Explain if Kekule’s model supports the following properties of benzene: i) The shape and bond angles seen in benzene ii) The C-C bond lengths in the molecule 4 The enthalpy change of hydrogenation of cyclohexene is -120kJmol-1, the enthalpy change of hydrogenation of benzene is -208kJmol-1. Use this information to explain why Kekule’s model does not fit the thermochemical data. 5 Draw the structures of the following molecules: i) chlorobenzene ii) methyl benzene iii) 1,2 dihydroxybenzene iv) phenol Learning Objective 6.0 Interpret spectroscopic data 6.1 Draw conclusions about unknown molecules based on spectroscopic data. 1 Identify which of the following molecules gave rise to the 13C NMR spectrum below. Explain how you reached your answer. a) Propane b) 2-methylpropane c) 2-methylpropan-1-ol 2 The mass spectrum of an alcohol is shown below i) Identify the molecular ion peak and the base peak. ii) Identify which of the following molecules gave rise to this mass spectrum. Explain how you reached your answer. a) butan-1-ol b) methanol c) propan-1-ol iii) Give the formula of the fragment of this molecule that produced the base peak. 3 This is a molecule of aspirin, a very commonly used painkiller. Draw up a table to show the KEY peaks that you would expect to see in the infrared spectrum of aspirin, identifying which bond has given rise to which peak. 4 Below is the 1H NMR spectrum for ethanol Source : http://www.chemguide.co.uk/analysis/nmr/highres.html i) Draw the full structural formula for ethanol and identify the three hydrogen environments that have given rise to the three peaks on the spectrum. ii) Explain the splitting patterns of the three peaks.