Aِcid Salt (Acidic Salt)

Salt in which there is only partial replacement of the acidic hydrogen of an acid by metal or other cations. For polybasic acids the formulae are of the type NaHSO₄ (sodium hydrogensulfate) and Na₃H(CO₃)₂.2H₂O (sodium sesquicarbonate). For monobasic acids such as HF the acid salts are of the form KHF2 (potassium hydrogen fluoride). Although the latter were at one time formulated as a normal salt plus excess acid (i.e. KF.HF) it is preferable to treat these as hydrogen-bonded systems of the type K⁺(F–H–F)⁻.