Booklet to help with unit 16

1. Booklet to help with unit 16 M4: predict the products of reactions of simple organic functional groups, given the reagents and conditions

2. Key words • Electrophile: An electron deficient species that is attracted to an electron rich centre (e.g. a double bond) • Nucleophile: An electron rich species that is attracted to an electron deficient centre (e.g. a slightly positive carbon) • Substitution reaction: Involves swapping over of one species for another • Addition reaction: Two species adding together to make one • Elimination reaction: When one species breaks into two • Reduction: Loss of oxygen or gain of hydrogen • Oxidation: Gain of oxygen or loss of hydrogen • Condensation reaction: Two species adding together to make one AND water molecules are released

3. Reactions of alkanes Substitution reactions Alkanes are substituted by halogens, such as chlorine and bromine CH4 + Cl2 CH3CI + HCl • This reaction only takes place in the presence of ultraviolet radiation, which produces highly reactive free radicals - free-radical substitution.

4. Task 1: predict the products of the following substitution reactions • CH4 + Br2 • C2H10+ Cl2 • CH3CI+ Cl2

5. Alkenes • Alkenes are unsaturated compounds with a C=C double bond. • The double bond has a high electron density - alkenes more reactive than alkanes • Alkenes react with electrophiles

6. Electrophilic addition reactions of alkenes • Electrophilic addition reaction: When a species is added to an electron rich centre of another species to make one species • Addition of bromine to alkene The Bromine molecule is added to the double bond of the alkene, and the double bonds become single bonds

7. + HBr • Addition of hydrogen bromide to alkene • Reduction of alkene with hydrogen The Hydrogen and bromine from the hydrogen bromide molecule is added to the double bond of the alkene, and the double bonds become single bonds The Hydrogen molecule is added to the double bond of the alkene, and the double bonds become single bonds

8. Task 2: Predict the products of the following addition reactions to alkenes • + Cl2 • + Br2 

9. + HCl • + HBr 

10. Main Type of Alcohols Alcohols can be classified as primary, secondary or tertiary, depending on how many alkyl groups are bonded to C-OH

11. Oxidation of primary alcohols • Heating and distilling a primary alcohol with limited acidified sodium dichromate (VI) produces an aldehyde • Refluxing a primary alcohol with excess acidified sodium dichromate (VI) produces a carboxylic acid

12. Oxidation of secondary alcohols • Refluxing a secondary alcohol with excess acidified sodium dichromate (VI) produces a ketone • Tertiary alcohols do not oxidise under normal conditions Oxidation of tertiary alcohols

13. Task 3: Predict the final products made heated with limited acidified sodium dichromate (VI) , and distilled 1. 2. refluxed with excess acidified sodium dichromate (VI)

14. refluxed with excess acidified sodium dichromate (VI) 3.

15. Aldehydes • These have a carbonyl group attached to the end of a carbon chain • Their names end in –al. Examples of aldehydes are ethanal and butanal

16. Ketones • These have a carbonyl group attached to the middle of a carbon chain • Their names end in -one. Examples of ketones are propan-2-one and butan-2-one

17. Oxidation of aldehydes and ketones • Refluxing an aldehyde with excess acidified sodium dichromate (VI) produces a carboxylic acid • Refluxing a ketone with excess acidified sodium dichromate (VI) does not produce a new product as no further oxidation is possible

18. Task 4: Predict the final products made 1. 2. Refluxed with excess acidified sodium dichromate (VI) refluxed with excess acidified sodium dichromate (VI)

19. Carboxylic acids • These have the functional group COOH • Their names are derived from the parent alkanes. Examples of carboxylic acids are methanoic acid, ethanoic acid and butanoic acid Methanoic acid Ethanoic acid Butanoic acid

20. Reacting carboxylic acids with LiAlH4 LiAlH4 • LiAlH4 reduces carboxylic acids to primary alcohols LiAlH4 Butanoic acid Butanol

21. Task 5: Predict the final products made 1. 2.

22. Esterification of carboxylic acids • In the presence of a concentrated acid, carboxylic acids and alcohols react to form esters and water + + H2O Butanoic acid Ethanol Ethyl butanoate Esterification is an example of a condensation reaction

23. Task 6: Predict the final products made heated with methanol and concentrated sulfuric acid 1. 2. heated with ethanol and concentrated sulfuric acid

24. heated with propanol and concentrated sulfuric acid 3. 4. heated with methanol and concentrated sulfuric acid

25. Esters • Esters are named according to the carboxylic acid and alcohol from which they are made from Ethyl ethanoate Methyl propanoate

26. Triglycerides • These are naturally occurring fats and oils • They are esters formed by esterification (condensation) between fatty acids (carboxylic acid) and glycerol (an alcohol) 3 Fatty acids + Glycerol Triglyceride + water 3 Carboxylic acids An alcohol An ester

27. Glycerol and fatty acids • Glycerol, with the formula C3H8O3 has three hydroxyl (OH) groups, all of which can take part in esterification reactions with a fatty acid • Stearic acid is an example of a fatty acid

28. Forming triglycerides A triglyceride

29. Task 7: Predict the final products made when glycerol reacts with the three fatty acids below

30. Task 8: Predict the final products made when glycerol reacts with the three fatty acids below

31. Task 9: Predict what fatty acids made the triglyceride below

32. Task 10: Predict what fatty acids made the triglyceride below