Thallous Perchlorate, T1C10 4, and periodate, Tl10 4, are interesting inasmuch as they are isomorphous with the corresponding potassium salts.
Perchloric acid is best prepared by distilling potassium perchlorate with concentrated sulphuric acid.
The fused mass is then extracted with water to remove potassium chloride, and warmed with hydrochloric acid to remove unaltered chlorate, and finally extracted with water again, when a residue of practically pure perchlorate is obtained.
Soc., 1886, p. 141), the decomposition of potassium chlorate by heat is not at all simple, the quantities of chloride and perchlorate produced depending on the temperature.
Chemically pure chloride of potassium is most conveniently prepared from the pure perchlorate by heating it in a platinum basin at the lowest temperature and then fusing the residue in a wellcovered platinum crucible.