The given sequence represents a series of chemical reactions involving iron (Fe) and various compounds. Here is a breakdown of each step:

1. Fe reacts with Cl2 to form FeCl3 (Iron(III) chloride).
2. FeCl3 reacts with water (H2O) to form Fe(OH)3 (Iron(III) hydroxide) and HCl (hydrochloric acid).
3. Fe(OH)3 undergoes dehydration to form Fe2O3 (Iron(III) oxide) and water (H2O).
4. Fe2O3 reacts with sulfuric acid (H2SO4) to form fe2(SO4)3 (Iron(III) sulfate) and water (H2O).
5. Fe2(SO4)3 reacts with hydrochloric acid (HCl) to regenerate FeCl3 (Iron(III) chloride).

Overall, this sequence represents a series of reactions where iron undergoes oxidation and reduction, forming different compounds along the way.