Test For Carbonyls: Aldehydes and Keytones
Abstract
Qualitative analysis of aldehydes and ketones was conducted in the experiment. Twelve test samples namely, acetophenone,2-butanone, 2-heptanone, benzaldehyde, 3-pentanone, hexanal, butyraldehyde, octanal, 4-heptanone, propiophenone, cyclohexanone, propionaldehyde were used in the experiment. Various parameters regarding the physical properties of aldehydes and ketones were determined using tests such as oxidation with sodium nitrate and sodium hydroxide, 2,4-dinitrophenylhydrazones test, Semicarbones test, Tollens’ test, Fehling’s test, Iodoform test, and the chromic acid test. The objectives of the experiment were met since the physical properties of the aldehydes and ketones were observed using these tests. Give an Unknown Letter D sample was tested with 2,4-dinitrophenylhydrazones test, Semicarbones test, Tollens’ test, Fehling’s test, Iodoform test, and the chromic acid test. Unknown D presumed miscible with a color change of Tang orange precipitate in 2,4-Dinitrophenyldrazones test. Semicarbones Test Unknown D had a melting of point 123C. Tollen’s test for unknown D tested negative with no formation of black precipitate of reduced silver. In Fehling’s test for unknown D tested negative with no formation of reddish precipitate of copper(I) oxide metallic deposits. Iodoform test of unknown D tested positive and Chromic Acid test for unknown D tested negative. Once conducting all test unknown D tested positive for a Keytone. Comparing results to all known samples that are keytones and viewing there melting points and properties unknown D is concluded to be 2-Heptanone.
Data/Results/Discussion
Generally, the chromic acid test reagent (Jones reagent) and Tollens reagent was to identify aldehyde. Iodoform test reagent is to identify methyl ketone.
