Which of the following is a redox reaction?
CuSO4+Zn→ZnSO4+CuCuSO_4 + Zn \rightarrow ZnSO_4 + CuCuSO4+Zn→ZnSO4+Cu
NaOH+HCl→NaCl+H2ONaOH + HCl \rightarrow NaCl + H_2ONaOH+HCl→NaCl+H2O
CaCO3→CaO+CO2CaCO_3 \rightarrow CaO + CO_2CaCO3→CaO+CO2
2Na+Cl2→2NaCl2Na + Cl_2 \rightarrow 2NaCl2Na+Cl2→2NaCl
Correct Answer: A — CuSO4+Zn→ZnSO4+CuCuSO_4 + Zn \rightarrow ZnSO_4 + CuCuSO4+Zn→ZnSO4+Cu
Explanation:
In CuSO4+Zn→ZnSO4+CuCuSO_4 + Zn \rightarrow ZnSO_4 + CuCuSO4+Zn→ZnSO4+Cu, zinc is oxidized (loses electrons) and copper is reduced (gains electrons). This simultaneous oxidation and reduction makes it a redox reaction.
