Question

Mg - MgO - MgSO4 - Mg(OH)2 - MgCl2

Answer 1

2Mg+O2=2MgO
MgO+SO3=MgSO4
MgSO4+Ba(OH)2=BaSO4+Mg(OH)2
Mg(OH)2+2HCl=MgCl2+2H2O

Answer 2

2Mg + O2 = 2MgO
MgO + H2SO4 = H2O + MgSO4
MgSO4 + 2KOH = K2SO4 + Mg(OH)2
Mg(OH)2 + 2HCl =2 H2O + MgCl2