Physical and chemical index Physical property Sodium bicarbonate was white crystal, fine crystalline monoclinic or opaque. Specific gravity 2.15. Odorless, salty, water soluble sodium bicarbonate, slightly soluble in ethanol. 25 water soluble in 10 water, about 18 degrees in 12 water soluble in water. Its aqueous solution by hydrolysis was slightly alkaline, at room temperature in the stable properties, heat easily decomposed, in more than 50 DEG C gradually decomposition, complete carbon dioxide loss at 270 DEG C, in air drying had no change, in the humid air in slow decomposition. Chemical property The heat is easy to decompose, and slowly decompose in the humid air. About the beginning of the reaction of CO at 50 degrees, 100 degrees in all into sodium carbonate. Rapid decomposition of the weak acid, its aqueous solution at 20 C, the decomposition of carbon dioxide and sodium carbonate, to the boiling point of all decomposition. Without stirring the solution made of the cold and to phenolphthalein test were only slightly alkaline reaction, placed or elevated temperature, the alkalinity increased. Fresh water solution pH 25 C 0.1mol/L value of 8.3. Low toxicity, half lethal dose (rat, oral) 4420mg/kg. Soda application Sodium bicarbonate can be directly used as pharmaceutical industry raw materials, used to treat hyperacidity. Can also be used for film production, tanning, mineral processing, smelting, heat treatment of metals, as well as for the fiber and rubber industry, etc.. At the same time as wool detergent, as well as for agricultural seed etc.. One of the most widely used osteoporosis agent in food industry for the production of biscuits, cakes, bread, bread and other is carbon dioxide in soda water generating agent; and alum composite alkaline baking soda, and soda ash composite for civilian soda; can also be used as butter preservation agent. Fire fighting equipment used in the production of acid and alkali fire extinguishers and foam. With the alum, H foaming agent in combination with uniform hole effect for rubber, sponge rubber industry production. Metallurgical industry used as a flux casting steel ingot. Machinery industry (Foundry) used as casting molding auxiliary mould. Printing and dyeing industry as dyeing and printing process, acid-base buffer, rear fabric dyeing and finishing the treatment agent. Baking soda stain can prevent yarn unevenness. Pharmaceutical industry used as raw material for making acid.