When an acid can only donate one proton, or a base can only accept one proton, we say these are monoprotic acids or bases. KOH Some acids have two or more dissociable protons. If a salt is formed in which any one of these protons is left, the salt is acidic. An amphoteric substance can act either as an acid or a base. Preparation of Acids Volatile acids have fairly low boiling points.
Examples are the hydrohalic acids.
2 SO 4 and H 3 PO 4 have higher boiling points. A classic example is BF 3 and NH 3 . The bond formed from the Lewis neutralization is called a coordinate covalent bond .