Question

How are hydrogen halides prepared?

Answer 1

1. By direct combination of hydrogen with halogen gases (like \[\ce{H2 + Cl2 -> 2HCl}\]).
2. By the reaction of a metallic halide (e.g., NaCl) with concentrated sulphuric acid, which releases hydrogen halide gas.
3. In the laboratory, hydrogen chloride gas is prepared by treating sodium chloride with concentrated sulphuric acid.

These methods are commonly used to prepare hydrogen halides such as HCl, HBr, and HI.