Hydrogen fluoride, an inorganic compound, is a white crystalline powder that dissolves in water and slightly in ethanol, with strong alkalinity. The pH of a 1mol/L solution is approximately 14, and the pKb is -0.04. It is mainly used for the preparation of lithium salts, lithium-based lubricants, electrolytes for alkaline batteries, and lithium bromide refrigerant absorbents.

It turns the purple litmus solution blue, the colorless phenolphthalein solution red, and its concentrated solution, as verified by experiments, can cause phenolphthalein to denature, changing the solution from red to colorless (similar to concentrated NaOH).

Primarily used for the preparation of lithium salts and lithium-based lubricants, electrolytes for alkaline batteries, lithium bromide refrigerant absorbents, etc.