Most evidence suggests that the proton in bisulfite ion is located on sulfur, giving rise to C3v symmetry. There is, however, some evidence from 17O NMR spectroscopy to suggest that two tautomeric forms of HSO3 exist in dynamic equilibrium, one having C3v symmetry (protonated at sulfur) and other Cs symmetry (protonated at oxygen). The C3v structure is supported by X-ray crystallography and, in aqueous solution, by Raman spectroscopy (ν(S–H) = 2500 cm−1).
Potassium Bisulfate
Potassium bisulfate is a chemical compound of the formula KHSO4. This compound is commonly used in the conversion of tartrates to bitartrates in wine. Potassium bisulfate is also used as a disintegrating agent in analytical chemistry. A solution of potassium bisulfate behaves like if the two congeners (K2SO4 and H2SO4) were side by side uncombined. Adding ethanol to a solution of potassium bisulfate precipitates out sulfate.
Sodium Bisulfate
Sodium bisulfate is produced by two methods. One method involves mixing stoichiometric quantities of sodium hydroxide and sulfuric acid which react to form sodium bisulfate and water.
NaOH + H2SO4 → NaHSO4 + H2O
A second production method involves reacting sodium chloride (salt) and sulfuric acid at elevated temperatures to produce sodium bisulfate and hydrogen chloride gas.
NaCl + H2SO4 → NaHSO4 + HCl
The liquid sodium bisulfate is sprayed and cooled so that it forms a solid bead. The hydrogen chloride gas is dissolved in water to produce hydrochloric acid as a useful byproduct of the reaction.
