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

 The  reaction  that  are   redox  reaction  are

 Cd  +HCl  →  CdCl2  +H2

2 ZnS  +3 O2→ 2 ZnO  + 2  SO2

CH4  +2O2→ CO2 + 2 H2O

Explanation

A  redox  reaction is a  type of  reaction  which involve  both  reduction  and  oxidation.

Cd +HCl → CdCl2 +H2  is a redox  equation  because

 Cd is  oxidized   from  oxidation state   0 to  2+  while H  is  reduced from oxidation state  1 t o 0

All combustion reaction   are redox reaction  therefore

2 ZnS  + 3 O2 → 2ZnO + 2 SO2

    and

CH4 +2 O2 →  CO2 + 2 H2O  are  redox reaction

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.

the answer is d.) potassium