—is next mixed with nitrate of soda and heated to 300° C., yielding sulphate of soda and nitrate of manganese, the latter, however, being at once decomposed into peroxide of manganese, and nitrogen peroxide, thus:—
| a. | MnSO4 + 2NaNO3 | = | Mn(NO3)2 + Na2SO4. |
| b. | Mn(NO3)2 | = | MnO2 + 2NO2. |
After the mass has cooled, the sulphate of soda is washed out, the residue yielding, according to the inventor, a material equal to native peroxide of manganese.
4. Schlösing. Manganese is acted upon with a mixture of hydrochloric and nitric acids, the degree of concentration of the acids being so regulated by the addition of water that the mixture yields only chlorine, whilst protonitrate of manganese is formed; this salt being calcined yields peroxide of manganese and nitric acid. The nitric acid aids the oxygen of the air in decomposing the hydrochloric acid.
The following equation will explain the successive stages of the reaction:—
| a. | 2HCl + 2HNO3 + MnO2 | = | Cl2 + Mn(NO3) + 2H2O. |
| b. | Mn(NO3)2 | = | MnO2 + 2NO2. |
| c. | 2NO2 + H2O + O | = | 2HNO3. |
5. Vogel. By decomposing chloride of copper by heat. The chloride in the crystalline
state is mixed with half its weight of sand and heated in earthenware retorts to 200° to 300° C., yielding chlorine gas, while the remaining protochloride of copper is reconverted into perchloride by the action of hydrochloric acid.
According to Laurens the reaction is as follows:—
| a. | 2CuCl2 | = | Cl2 + 2Cu22Cl2. |
| b. | Cu2Cl2 + 2HCl + O | = | H2O + 2CuCl2. |