Question

Which of the following set of ions act as oxidising agents?

• A. Ce⁴⁺ and Tb⁴⁺
• B. La³⁺ and Lu³⁺
• C. Eu²⁺ and Yb²⁺
• D. Eu²⁺ and Tb⁴⁺

Answer 1

The Correct Option is A

To determine which set of ions act as oxidizing agents, we need to consider the oxidation states of the given ions. An oxidizing agent is a substance that gains electrons and, in the process, gets reduced.

1. Ce⁴⁺ and Tb⁴⁺: These ions have higher oxidation states which they can reduce to more stable lower oxidation states (Ce³⁺ and Tb³⁺) by accepting electrons. Hence, they act as oxidizing agents.
2. La³⁺ and Lu³⁺: Both Lanthanum (La) and Lutetium (Lu) are in their most stable oxidation states as La³⁺ and Lu³⁺, respectively. They do not tend to accept electrons to reduce further, thereby acting less likely as oxidizing agents.
3. Eu²⁺ and Yb²⁺: Europium (Eu) and Ytterbium (Yb) are often found in the +2 oxidation state, which is not a strong oxidizing state. They are more likely to lose electrons to reach +3, making them reducing agents.
4. Eu²⁺ and Tb⁴⁺: While Eu²⁺ is more of a reducing agent, Tb⁴⁺ can act as an oxidizing agent. However, since one of the ions here does not act as an oxidizing agent, this set is not primarily an oxidizing agent."

Thus, the set of ions that act as oxidizing agents is Ce⁴⁺ and Tb⁴⁺.