Question

Sulphuric acid can be used in the preparation of hydrogen chloride but not for preparation of hydrogen iodide

Answer 1

sulphuric acid is pretty easy to manufacture since sulphur is abundantly available and processes for the manufacture of sulphuric acid has been well worked out and commercialized it is also cheaper to produce than many other acid so you always want to leverage your production of other acid is weaker cheap acid in your progress