Colorless crystals or white crystal powder with sweet and sour taste, sparingly soluble in water, freely soluble in dilute mineral acid, alkaline solution or borax solution and insoluble in acetic acid or ethanol, relative density 1.984. Uses: Served as capacity analytical reagent, buffer and reducing agent, also as leavening agent in food industry Served as capacity analytical reagent, buffer and reducing agent, also as leavening agent in food industry