trioxide
- n an oxide containing three atoms of oxygen in the molecule
- Arsenic trichloride, when mixed with enough water, breaks down into arsenic trioxide and hydrochloric acid in a chemical reaction that increases its corrosive properties.
- Chief culprits in the Donora, London and New York smog disasters were probably sulphur dioxide and sulphur trioxide, which, either in gaseous form or converted into sulphuric .