Features: Soluble in water, slightly soluble in ethanol. The aqueous solutionis slightly alkaline due to hydrolysis, and the properties are stable at room temperature, easy to decompose by heating, no change in the dry air and slow decomposition in the moist air. With stability, only slightly alkaline reaction of phenolphthalexone, placed or elevated temperature, the increase of alkaline. Can react with acid, alkali and salt, hydrolysis, heating, ionization and so on.