acid salt 
noun Chemistry
A salt formed by incomplete replacement of the hydrogen of an acid, e.g. potassium hydrogen sulphate (KHSO4).Tartaric acid is of even further interest because its potassium acid salt, potassium tartrate or cream of tartar, while being moderately soluble in grape juice, is only partially soluble in alcoholic solutions such as wine....
- Berberine hemi-sulphate is an acid salt of the alkaloid berberine, which has been used supposedly to confirm the presence of suberin in plant roots.
- Soap is a unique substance of potassium fatty acid salts, produced through a chemical reaction called saponification.