Sodium bisulphate is commonly called as Niter Cake because it was formally obtained by the obsolete process of reacting nitrate, or niter, with sulphuric acid: NaNO 3 + H 2 SO 4 → NaHSO 4 + HNO 3 It may also be formed when salt is moderately heated with sulphuric acid: NaCl + H 2 SO 4 → NaHSO 4 + HCl It is an easy handled dry material that react like sulphuric acid. Major uses are in the manufacture of acid type toilet bowl cleaners and for industrial cleaning and metal pickling. Minor uses are in dye baths, carbonizing wool and various chemical processes. Sodium Bisulphite Sodium bisulfite finds industrial use either in solution or as a solid. The total solid is of the anhydrous form, and the pure reagent has the formula NaHSO 3 . The commercial product consist almost entirely of Na 2 S 2 O 5 (sodium pyrosulfite), or sodium metabisulfite, which is the dehydrated derivative of two molecules of sodium bisulfite. The solution may be easily shipped, stored