Carboxylic Acids
Carboxylic acids are weak organic acids which are found in many common food stuffs, such as vinegar and citrus fruits.
The acids are soluble in water due to their ability to hydrogen-bond with water. They are capable of hydrogen-bonding because of the highly polar O-H bond they contain. The large differences in electronegativities of the Hydrogen and Oxygen create a delta +ve H and a delta -ve O. These are the same charges which are seen in waterm hence their ability to bond. The carboxylic acids are also able to dissociate in water into a H+ ion and a RCOO- ion. The presence of the H+ ion explains why they act as acids when in solution.
It is worth noting that alcohols also contain the O-H group but are unable to dissociate in water. It is only because the OH group is in close proximity to the polar C=O bond in a carbxylic acid that they are able to dissociate more fully.
Carboxylic acids can be produced by refluxing a primary alcohol or an aldehyde with an acidified potasssium dichromate (VI). Or the acid can be produced by the acid hydrolysis of an ester.