Question

What are the function of potassium hydro solution concentrated tetraoxosulphate (6) acid and heated iron filling in the preparation of nitrogen from air

Answer 1

This is a new one on me. I have idea what potassiu hydro solution is. Perhaps you meant to write potassium hydroxide. There is a process for obtaining N2 gas by iron (burning) Fe filings (note: not fillings) in sealed container of air in which the Fe is oxidized to Fe2O3. The O2 is removed but the N2 remaining is not pure N2. The remainder is N2, with impurities of Ar, and other gases such as Ar (about 1%). As for the role of KOH (if that is what you meant for potassium hydro solution) and H2SO4, I don't know other than as a way of introducing heat, However, using those as solutions intodudes H2O vaport into the sealed reaction vessel which in my opinion inroduces H2O vapor as a contaminant of the N2 in addtion to the other impurities. You might want to re-read and rephrase the question to make more sense.