150 likes | 160 Views
Explore the functional group, physical properties, and chemical reactions of aldehydes and ketones. Learn about their boiling points, hydrogen bonding capabilities, characteristic reactions, oxidation, reduction, and nucleophilic additions. Discover how these compounds can be identified through derivative products.
E N D
Aldehydes and Ketones AH Chemistry Unit 3(b)
Functional Group • What is the functional group of the aldehydes and ketones? • What type of bonds link the C and O atoms?
Physical Properties • How do the boiling points compare to alkanes? • Why? • How do the boiling points compare to alcohols? • Why?
Can aldehydes and ketones set up hydrogen bonds with each other? • Can they set them up with water?
Chemical reactions • What are the characteristic reactions of aledehydes and ketones? • Reduction • Nucleophilic addition • Nucleophilic addition-elimination • Which is more susceptible to nucleophilic attack, aldehyde or ketone? • Why?
Oxidation • What reagents can be used to oxidise aldehydes?
Reduction • Aldehydes and ketones can be reduced to produce alcohols. • The reducing agent of choice is LiAlH4 - lithium aluminium hydride • Able to transfer a hydride ion to the partially positive carbon atom of the carbonyl group • Musty be carried out in anhydrous conditions (in ether)
Nucleophilic addition • With HCN, producing cyanohydrins....
The cyanohydrins can be hydrolysed to produce hydroxy carboxylic acids
Nucleophilic addition-elimination - With hydrazine, H2N-NH2 - Produces hydrozones
Nucleophilic addition Elimination CONDENSATION
- With 2,4-dinitrophenylhydrazine - Produces 2,4-dinitrophenylhydrozones These products are “derivatives”. They are crystalline solids with characteristic melting points. The melting point of the derivative can be used to identify the orignial carbonyl compound.