Insoluble in water (0.1g/100mL, 25℃). Slightly hygroscopic. Heating to 100°C gradually loses crystal water. Physical and chemical properties: Physical properties Solubility: 0.1 M HCl: 0.01 M at 20 °C, clear, colorless White crystalline powder, odorless, slightly hygroscopic, slightly soluble in water, soluble in acid, and almost insoluble in ethanol. The crystal water gradually loses water when heated to 100℃, and completely loses water at 120℃.