Instead, hydrogen bromide is prepared by fist reacting bromine with phosphorus to form phosphorus tribromide:
Next, PBr3 is treated with water to yield HBr:
Hydrogen iodide can be prepared in a similar manner.
The high re activity of HF is demonstrated by the fact that it attacks silica and silicates:
This property makes HF suitable for etching glass and is the reason that hydrogen fluoride must be kept in plastic or inert metal (for example, Pt) containers. hydrogen fluoride is used in the manufacture of Freon's for example:
and in the production of aluminium. Hydrogen chloride is used in the