Final answer:
Chromium reagents oxidize a primary alcohol to an aldehyde, which can further be oxidized to a carboxylic acid. Aldehydes are more easily oxidized than alcohols and directly yield carboxylic acids when treated with a chromium reagent.
Step-by-step explanation:
When a chromium reagent such as Jones reagent, chromic acid, or potassium dichromate is used to oxidize a primary alcohol, it gets converted to an aldehyde. For example, ethanol (a primary alcohol) when oxidized, forms acetaldehyde. The chromium in the reagent is reduced from Cr6+ to Cr3+ during this reaction. Further oxidation of the aldehyde can lead to the formation of a carboxylic acid.
With regards to an aldehyde, it is more easily oxidized than an alcohol and directly converts to a carboxylic acid with the introduction of a chromium reagent. This is an important reaction in both synthetic organic chemistry and analytical chemistry, such as using the reaction to test for the presence of alcohol in breathalyzer tests by law enforcement.