Which of these reactions are redox reactions? Check all that apply.
Cd + HCl → CdCl2 + H2
CuCl2 + Na2S → 2NaCl + CuS
CaCO3 → CaO + CO2
2ZnS + 3O2 → 2ZnO + 2SO2
CH4 + 2O2 → CO2 + 2H2O
Cd + HCl → CdCl2 + H2
CuCl2 + Na2S → 2NaCl + CuS
CaCO3 → CaO + CO2
2ZnS + 3O2 → 2ZnO + 2SO2
CH4 + 2O2 → CO2 + 2H2O