KOH + H3PO4 -> Ca(OH)2 + H2SO4 -> Ba(OH) + HNO3 -> Fe(OH)2 + H2S -> Fe(OH)3 + H2S ->
1 K3PO4+H2O
2 CaSO4+H2O
3 Ba(NO3)2+H2O
4 FeS2+H2O
5 FeS3+H2O
3KOH+H₃PO₄=K₃PO₄+3H₂O
Ca(OH)₂+H₂SO₄=CaSO₄+2H₂O
Ba(OH)₂+2HNO₃=Ba(NO₃)₂+2H₂O
Fe(OH)₂+H₂S=FeS↓+2H₂O
2Fe(OH)₃+3H₂S=Fe₂S₃+6H₂O