# Is every compound that has a H-bond donating group soluble in water? [closed]

I am wondering if there is any general rule of thumb

• There are hardly any such simple generalisations that can be made in chemistry for the solubility of compounds. If the compound has a large nonpolar domain, clearly it won't be water soluble despite having an -OH group. Jul 19 '18 at 1:44
• If we are making generalisations, I would say they are harmful. ;-)
– Karl
Jul 19 '18 at 5:20

Definitely not. For instance, palmitic acid with a pK$_\mathrm{a}$ of 4.75 has a water solubility of only 0.04 mg/L.

A general rule of thumb is that every oxygen can solubilize four carbon atoms but there are many exceptions. I addressed a similar question here.

Nitrogen also makes the compound more soluble, but there it depends very much on the pH.