Sodium bisulfate (chemical formula: NaHSO4), also known as acid sodium sulfate. Its anhydrous substance is hygroscopic. The aqueous solution is acidic, and the pH of a 0.1mol/L sodium bisulfate solution is about 1.4. Sodium bisulfate can be obtained in two ways. By mixing sodium hydroxide and sulfuric acid in such amounts, sodium bisulfate and water can be obtained. NaOH + H2SO4 → NaHSO4 + H2O Sodium chloride (table salt) and sulfuric acid can react at high temperatures to produce sodium bisulfate and hydrogen chloride gas. NaCl + H2SO4 → NaHSO4 + HCl household cleaner (45% solution); extraction of metallic silver; reduction of the alkalinity of swimming pool water; pet food; 4 as a preservative when analyzing soil and water samples in the laboratory; Used in the preparation of sulfuric acid.