How to analyze an unknown aldehyde or ketone?
In this experiment, you will analyze an unknown aldehyde or ketone by performing classification tests, by measuring the refractive index and boiling point, and by preparing a derivative and measuring its melting point. You will identify your unknown by comparing its data with literature values.
What is a positive aldehyde test?
A positive test for an aldehyde will be a silver mirror formed on the test tube if the test tube was clean; if the test tube was not clean, a black precipitate will form. Record your results on the report sheet. Clean the test tubes with 1 M nitric acid.
How does Tollens reagent oxidize an aldehyde into a carboxylic acid?
Tollens’ reagent oxidizes an aldehyde into the corresponding carboxylic acid. The reaction is accompanied by the reduction of silver ions in Tollens’ reagent into metallic silver, which, if the test is carried out in a clean glass test tube, forms a mirror on the test tube. eg:
Do aldehydes react with alcohols?
Aldehydes and ketones react with 2,4-dinitrophenylhydrazine reagent to form yellow, orange, or reddish-orange precipitates, whereas alcohols do not react. Formation of a precipitate therefore indicates the presence of an aldehyde or ketone. The precipitate from this test also serves as a solid derivative.
Identification of an Unknown – Alcohols Aldehydes