Ba+O2= Ag+S= HgO= FeO+H2= KOH+H2SO4= Fe (OH)3=
2Ba +O₂ = 2BaO 2Ag + S =Ag₂S 2HgO = 2Hg +O₂ FeO + H₂ = Fe + H₂O 2KOH + H₂SO₄= K₂SO₄ + 2H₂O 2Fe(OH)₃= Fe₂O₃ + 3H₂O