Answer: Ionic compounds are held together by the virtue of their opposing charges. Na+Cl- for example. If we consider Hg+(2Cl-)2, a mercuric chloride, the solubility is much less. Ba++(SO)4 Barium Sulphate, is highly insoluble; all differ by the relative attractiveness by Differing opposing charge(s).
Acids are very similar, consider Formic Acid, HCOOH, the simplest of the Carboxylic Acids. It dissociates more than say Benzoic Acid, C6H5-COOH. But neither disassociate as fully as Nitric Acid HNO3.
So the relative disassociation of the H+ (proton), or H3O+, (Hydronium ion), from any of these in water vary for a number of reasons we need not consider now.
Here is a “Tricky One!” (And very nasty). Take HF liquid or gas. This is one of the strongest acids on Earth - AS A LIQUID compound OR GAS. It will dissociate essentially near completion! Eat the floor, and is very dangerous.
NOW - HF (aqueous). The HF is in water. Very like HCl? NO! Why you may ask...The Electrophilic nature of Fluorine, “bathed in water, with an H+ all its own”, doesn’t let it go as easily!
HF is HIGHLY ordered in water, you can almost imagine a sort of “Hydrated matrix”, little HFs in endless rows...
BUT BE WARNED - even the aqueous HF is so reactive it will dissolve bone!
(I was told it was extremely painful; and did not appear to heal for weeks!)
Explanation: so, both types of compounds have a similarity, held together by the strength of their opposing charges or the degree of dissociation, (using water for simplicity).
That should do it.
