AS and A2 Chemistry notes and resources (WJEC specification) - UNIT CH4 Spectroscopy and Organic Chemistry (Analysing and building molecules)

This unit builds on the foundation ideas of spectroscopy and basic organic chemistry introduced at AS level and goes on to explore these concepts in more detail. It also explores the use of these topics in structure elucidation, in synthesis and in industrial and environmental applications.

11.2 - Aldehydes and ketones

Candidates should be able to:

(a) describe the formation of aldehydes and ketones by the oxidation of primary and secondary alcohols respectively;

(b) describe how aldehydes and ketones may be distinguished by their relative ease of oxidation using Tollens' reagent and Fehling's reagent *;

(c) recall the use of NaBH4 to reduce aldehydes and ketones and state the organic products formed *;

(d) describe the reaction of aldehydes and ketones with 2,4-dinitrophenylhydrazine reagent as a nucleophilic addition-elimination (condensation) reaction and explain the use of this reaction in showing the presence of a carbonyl group and in identifying specific aldehydes and ketones by determining the melting temperatures of the purified products;

(e) describe and understand the mechanism of the addition of HCN to carbonyl compounds as an example of a nucleophilic addition reaction ¢Ó;

(f) describe how the triiodomethane (iodoform) test is carried out and explain its use in detecting CH3CO . groups or their precursors.