4Cr + 3O2 = 2Cr2O3
Cr2O3 + 6HCl = 2CrCl3 + 3H2O
CrCl3 + 3NaOH = Cr(OH)3 + 3NaCl
2Cr(OH)3 --(t) = Cr2O3 + 3H2O
<span>Cr2O3 + 3H2 = 2Cr + 3H2O</span>
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2K(+)+SiO3(-2)+2H(+)+2Cl(-)=2K(+)+2Cl(-)+H2O+SiO2
2H(+)+SiO3(-2)=H2O+SiO2
Ответ:
Cu(OH)2 + Zn → Cu + Zn(OH)2
2 HCl + Zn → H2 + ZnCl2
Cu(OH)2 + 2 HNO3 → 2 H2O + Cu(NO3)2
2 HCl + Cu(OH)2→ 2 H2O + CuCl2
CaO + 2 HCl → H2O + CaCl2
CaO + 2 HNO3 → H2O + Ca(NO3)2