| Normal bismuth sulphite has not yet been obtained, but a number of basic compounds have been obtained. They are all white, powdery substances obtained by the action of a solution of bismuth nitrate in nitric acid upon a solution of sodium sulphite. The nature of the product depends upon the temperature and concentration of the solutions. Among the sulphites that have been described are: 9(BiO)2SO3.(BiOH)SO3.2H2O, 4(BiO)2SO3.(BiOH)SO3. 5H2O, 2(BiO)2SO3.3(BiOH)SO3.2H2O, 3(BiO)2SO3.7(BiOH)SO3.10H2O, (BiO)2SO3.3(BiOH)SO3.H2O. By the action of hot sulphurous acid upon bismuth trioxide, a white, powdery compound has been obtained to which is ascribed the formula (BiO)2SO3.2(BiOH)SO3.4H2O. It is stable in air, insoluble in water, but slightly soluble in sulphurous acid, from which it may be reprecipitated by dilution. |