Potassium in 1809, Ludwig Wilhelm Gilbert proposed the name "Kalium" for Davy's "potassium". In 1814, the Swedish chemist Berzelius advocated the name "kalium" for potassium, with the chemical symbol "K". The English and French speaking countries adopted Davy and Gay-Lussac/Thénard's name Potassium, while the Germanic countries adopted Gilbert/Klaproth's name Kalium. The "Gold Book" of the International Union of Physical and Applied Chemistry has designated the official chemical symbol as K. Potassium is the second least dense metal after lithium. It is a soft solid with a low melting point, and can be easily cut with a knife. Freshly cut potassium is
Potassium pyrosulfate OSOSO. The oxidation state of sulfur in this compound is +6. Potassium pyrosulfate is used in analytical chemistry; samples are fused with potassium pyrosulfate, (or a mixture of potassium pyrosulfate and potassium fluoride) to ensure complete dissolution prior to a quantitative analysis. The compound is also present in a catalyst in conjunction with vanadium(V) oxide in the industrial production of sulfur trioxide. Potassium pyrosulfate Potassium pyrosulfate, or potassium disulfate, is an inorganic compound with the chemical formula KSO. Potassium pyrosulfate is obtained by the thermal decomposition of other salts, most directly from potassium bisulfate: Temperatures above 600°C further decompose potassium