Which of the following is NOT an example of oxidation?

• A. Cl_2 to 2Cl^{-}
• B. Fe to Fe^{3+}
• C. Zn to Zn^{2+}
• D. Cu to Cu^{2+}

Answer: (A)

Verified step by step guidance

1. Recall the definition of oxidation: it is the loss of electrons by a species, which results in an increase in its oxidation state.
2. Analyze each option by determining whether the species is losing or gaining electrons:
3. For Cl_2 to 2Cl^{-}: Chlorine molecules (Cl_2) are converted to chloride ions (Cl^{-}). Since Cl_2 is neutral and Cl^{-} has a negative charge, chlorine gains electrons here, which means it is reduced, not oxidized.
4. For Fe to Fe^{3+}: Iron (Fe) goes from a neutral atom to a +3 charged ion, indicating it loses 3 electrons, so this is oxidation.
5. For Zn to Zn^{2+} and Cu to Cu^{2+}: Both zinc and copper atoms lose electrons to form positively charged ions, which are examples of oxidation.