3 ВАРИАНТ Cu +02=Cuo
Fe2O3 + HCI = FeCl3 + H2O
Ba + H2O = Ba(OH)2 + H2
SO2 + H2O + H2SO3
CuCl2 + KOH= Cu(OH)2+KCI
Ca(OH)2 + HNO3 =Ca(NO3)2+ H2O
AgNO3 + NaBr = AgBr] + NaNO3
Cu + Hg(NO3)2 = Cu(NO3)2 + Hg
Mg + HCl = MgCl2 + H2 1

2Cu + O₂ → 2CuO

Fe₂O₃ + 6HCI → 2FeCl₃ + 3H₂O

Ba + 2H₂O → Ba(OH)₂ + H₂↑

SO₂ + H₂O → H₂SO₃

CuCl₂ + 2KOH → Cu(OH)₂↓ + 2KCI

Ca(OH)₂ + 2HNO₃ → Ca(NO₃)₂+ 2H₂O

AgNO₃ + NaBr → AgBr↓ + NaNO3₃

Cu + Hg(NO₃)₂ → Cu(NO₃)₂ + Hg ↓

Mg + 2HCl → MgCl₂ + H₂↑