what evidence is there that caboxylic acids are soluble or insoluble in aqueous solutions?

Question

in terms of molecular structure of the acids

Answer 1

They can participate in H-bonding with water. The [=O] H-bonds to the H of water. The [-OH] H-bonds to the O of water. The larger the chain of carbons, the less soluble they become.

Answer 2

It depends on the amount of hydrophobic hydrocarbon content compared with the number of COOH groups. Lower molecular weight acids like CH3COOH and CH3CH2COOH are soluble. Stearic acid, CH3(CH2)16COOH is almost completely insoluble. Citric acid has three hydrocarbon C's in it, but also three -COOH's and an -OH. So it's soluble.