Question

Mg > MgO > MgSO4 > Mg(OH)2 > MgO > Mg
P > P2O5 > H3PO4 > K3PO4 > KCl

Answer 1

4P+5O2=2P2O5

P2O5+3H2O=2H3PO4

H3PO4+3KOH=K3PO4+3H2O

K3PO4+HCl=KCl+H3PO4

Answer 2

Mg+o2=Mgo Mgo+H2so4=Mgso4; MgSo4+KoH=Mg(oH)2+K2so4; Mg(oH)2 =MgO+H2O.