Arsenic trifluoride, also known as arsenic(III) fluoride, is a chemical compound. Its chemical formula is AsF3. It has arsenic and fluoride ions in it. The arsenic is in its +3 oxidation state.
Arsenic trifluoride is a colorless liquid. It melts at -8.5°C and boils at 60.4°C. It is highly toxic. It reacts with water to make arsenous acid and hydrofluoric acid, both very dangerous acids.
It is made by reacting arsenic trioxide with hydrofluoric acid or by reacting excess arsenic with fluorine.
It is used to change nonmetal chlorides to fluorides.