2 Ca + O2 = 2 CaO
CaO + H2O = Ca(OH)2
3 Ca(OH)2 + 2 K3PO4 = Ca3(PO4)2 + 6 KOH
2 Cu + O2 = 2 CuO
CuO + 2 HCl = CuCl2 + H2O
CuCl2 + 2 NaOH = Cu(OH)2 + 2 NaCl
Cu(OH)2 = CuO + H2O
CuO + H2 = Cu + H2O
4 P + 5 O2 = 2 P2O5
P2O5 + 3 H2O = 2 H3PO4
2 H3PO4 + 3 Ca = Ca3(PO4)2 + 3 H2