This reaction pathway shows the conversion of magnesium oxide (MgO) to magnesium phosphate (Mg3(PO4)2) through several intermediate steps involving magnesium chloride (MgCl2) and magnesium carbonate (MgCO3).

MgO is first converted to MgCl2 by reacting with hydrochloric acid (HCl).MgCl2 is then converted to MgCO3 by reacting with sodium carbonate (Na2CO3).MgCO3 is then converted back to MgCl2 by reacting with hydrochloric acid (HCl) again.Finally, MgCl2 is converted to Mg3(PO4)2 by reacting with phosphoric acid (H3PO4).

This reaction pathway illustrates the different chemical reactions involved in the conversion of magnesium oxide to magnesium phosphate.