Potassium Fluoride
Potassium Fluoride
HOW IT IS MADE
In one method for making Potassium fluoride, Potassium carbonate (K2CO3) is dissolved in hydrofluoric acid, resulting in the formation of Potassium bifluoride (KHF2): K2CO3 + 2H2F2 → 2KHF2 + CO2 + H2O. The Potassium bifluoride is then heated to form Potassium fluoride and hydrogen fluoride: KHF2 → KF + HF.
KEY FACTS
OTHER NAMES:
Potassium monofluoride
FORMULA:
KF
ELEMENTS:
Potassium, Fluorine
COMPOUND TYPE:
Binary salt (inorganic)
STATE:
Solid
MOLECULAR WEIGHT:
58.10 g/mol
MELTING POINT:
858°C(1580°F)
BOILING POINT:
1502°C(2736°F)
SOLUBILITY:
Potassium fluoride can also be prepared by the direct reaction between hydrofluoric acid and potassium hydroxide: H2F2 + 2KOH → 2KF + 2H2O. The potassium fluoride thus formed is then dried and crystallized or converted to powder form.
COMMON USES AND POTENTIAL HAZARDS
Potassium fluoride is used as a fluoridating agent—a substance that provides fluorine atoms to other compounds—in the preparation of organic chemicals. It also finds some use in the field of metallurgy, where it is used as a flux, to finish metals, to make coatings for metals, and in tin plating. Potassium fluoride is used to frost and etches glass, as in the manufacture of some optical glasses, and to make insecticides, pesticides, and disinfectants.
Potassium fluoride is irritating to the skin, eyes, and respiratory system. It is moderately toxic by ingestion, causing nausea, vomiting, diarrhoea, and stomach pains. In larger doses, it can cause damage to the brain, kidneys, and heart. Long-term exposure to potassium fluoride can cause damage to the teeth and bones. One condition that can develop is called fluorosis. Symptoms of the condition include brittle bones, weight loss, anaemia, hardening of the ligaments, and stiffness of the joints.