Viết PTPU hoàn thành chuỗi phản ứng sau

The chemical reactions you have listed are as follows:

1. Fe -> Fe2(SO4)3: Iron reacts with sulfuric acid to form iron(III) sulfate.
2. Fe2(SO4)3 -> FeCl3: Iron(III) sulfate reacts with hydrochloric acid to form iron(III) chloride.
3. FeCl3 -> Fe(OH)3: Iron(III) chloride reacts with sodium hydroxide to form iron(III) hydroxide.
4. Fe(OH)3 -> Fe2O3: Iron(III) hydroxide undergoes dehydration to form iron(III) oxide.
5. Fe2O3 -> Fe: Iron(III) oxide is reduced to elemental iron.
6. Fe -> Fe3O4: Elemental iron reacts with oxygen to form iron(II,III) oxide (also known as magnetite).