Question

Which of the following ions is the strongest oxidizing agent? (Atomic Number of Ce = 58, Eu = 63, Tb = 65, Lu = 71)

• A. \( {Lu}^{3+} \)
• B. \( {Eu}^{2+} \)
• C. \( {Tb}^{4+} \)
• D. \( {Ce}^{3+} \)

Hint:

Ions with a higher charge and smaller size are generally stronger oxidizing agents because they have a higher tendency to accept electrons and achieve a stable electronic configuration.

Answer 1

The Correct Option is C

Strength of an Oxidizing Agent 

Given: The strength of an oxidizing agent depends on its ability to accept electrons. A higher positive charge and smaller size typically make an ion a stronger oxidizing agent because the ion is more eager to accept electrons to achieve a stable electronic configuration.

Analysis of Each Ion

1. \( \text{Lu}^{3+} \)

- This is the 3+ cation of lanthanum (atomic number 71). - Although it is a highly charged ion, it is relatively large compared to other lanthanides. - **Conclusion**: It is a strong oxidizing agent but not as strong as other ions with higher charges and smaller sizes.

2. \( \text{Eu}^{2+} \)

- This is the 2+ cation of europium (atomic number 63). - The Eu\(^{2+}\) ion is in the +2 oxidation state and is a stronger reducing agent compared to its +3 oxidation state. - **Conclusion**: Eu\(^{2+}\) is a reducing agent and not an oxidizing agent.

3. \( \text{Tb}^{4+} \)

- This is the 4+ cation of terbium (atomic number 65). - The Tb\(^{4+}\) ion is highly charged and has a very high tendency to accept electrons, making it a very strong oxidizing agent. - **Conclusion**: The Tb\(^{4+}\) ion is the strongest oxidizing agent among the ions listed.

4. \( \text{Ce}^{3+} \)

- This is the 3+ cation of cerium (atomic number 58). - The Ce\(^{3+}\) ion is a strong oxidizing agent but not as strong as Tb\(^{4+}\). - **Conclusion**: While a strong oxidizing agent, it is weaker compared to Tb\(^{4+}\).

Conclusion:

The strongest oxidizing agent among the given ions is \( \boxed{\text{Tb}^{4+}} \), which is the most eager to accept electrons due to its high charge and smaller size compared to the other ions.