Raffles Institution H2 Chem Carbonyl Compounds (Student).pdf

Page 1 of 22 Raffles Institution Year 6 H2 Chemistry 2025 Lecture Notes 18 – Carbonyl Compounds Lecturer: Dr Jackson Koh I Learning Objectives Candidates should be able to (a) describe the formation of aldehydes and ketones from, and their reduction to, primary and secondary alcohols respectively. (b) describe the mechanism of the nucleophilic addition reactions of hydrogen cyanide with aldehydes and ketones. (c) explain the differences in reactivity between carbonyl compounds and alkenes towards nucleophilic reagents such as lithium aluminium hydride and hydrogen cyanide. (d) describe the use of 2,4 -dinitrophenylhydrazine (2,4 -DNPH) to detect the presence of carbonyl compounds. (e) deduce the nature (aldehyde or ketone) of an unknown carbonyl compound from the results of simple tests (i.e. Fehling’s and Tollens’ reagents; ease of oxidation). (f) deduce the presence of a CH 3CO− group in a carbonyl compound from its reaction with alkaline aqueous iodine to form tri-iodomethane II References 1. Understanding Advanced Organic and Analytical Chemistry by Kim Seng Chan & Jeanne Tan. 2. Chemistry in Context by G. C. Hill & J. S. Holman 3. ‘A’ Level Chemistry by E. N. Ramsden 4. Organic Chemistry by John McMurry III Contents 1. Introduction ........................................................................................................................................ 2 2. Nomenclature .................................................................................................................................... 3 3. Physical properties ............................................................................................................................ 4 3.1 Boiling points ............................................................................................................................... 4 3.2 Solubility ...................................................................................................................................... 4 4. Preparation methods for carbonyl compounds .................................................................................. 5 4.1 Oxidation of alcohols ................................................................................................................... 5 4.2 Oxidation of alkenes .................................................................................................................... 6 4.3 Electrophilic substitution of benzene ........................................................................................... 6 5. Chemical properties of carbonyl compounds .................................................................................... 7 5.1 Relative reactivities of carbonyl compounds towards nucleophilic attack .................................. 8 5.2 Formation of cyanohydrins – Nucleophilic addition .................................................