The chemical reactions shown are:

Iron $Fe$ reacts with oxygen $O_2$ to form iron $III$ oxide $F{e}_2{O}_3$.Iron $III$ oxide reacts with hydrochloric acid $HCl$ to form iron $III$ chloride $FeC{l}_3$.Iron $III$ chloride reacts with sodium phosphate $N{a}_{3}P{O}_4$ to form iron $III$ phosphate $FeP{O}_4$.