4.  Physical Property: Astringent taste; the relative density of 2.532; melting point 851 °C; solubility 21g 20 °C.

5.  Chemical properties: Strong stability, but also can be decomposed at high temperature to produce sodium oxide and carbon dioxide. Strong moisture absorption, it is easy to form a lump, do not decompose at high temperatures.

6.  Solubility: soluble in water, slightly soluble in ethanol, insoluble in alcohol.