Final answer:
The redox reaction is CuCl₂ + NaOH → NaCl + Cu(OH)₂. The redox reaction among the given options is (a) H₂ + O₂ → H₂O, where hydrogen is oxidized and oxygen is reduced.
Step-by-step explanation:
In the given options, the redox reaction is option d) CuCl₂ + NaOH → NaCl + Cu(OH)₂.
In this reaction, copper(II) chloride (CuCl₂) is reduced to copper(II) hydroxide (Cu(OH)₂) and sodium hydroxide (NaOH) is oxidized to sodium chloride (NaCl).
The oxidation state of copper in CuCl₂ changes from +2 to +2, so it is reduced. The oxidation state of sodium in NaOH changes from -1 to 0, so it is oxidized.
2, so this is a redox reaction.Therefore, the correct answer is option (a) H₂ + O₂ → H₂O.