Strong reducing and oxidizing agents among the following , respectively, are

Options

A. `Ce^(3+)` and `Ce^(4+)`
B. `Ce^(4+)` and `Tb^(4+)`
C. `Ce^(4+)` and `Eu^(2+)`
D. `Eu^(2+)` and `Ce^(4+)`

Answer

To solve the problem of identifying the strong reducing and oxidizing agents among the given options, we will follow these steps:

### Step 1: Understand the Concept of Reducing and Oxidizing Agents
- A reducing agent is a substance that donates electrons and is oxidized in the process. It typically has a lower oxidation state and can easily lose electrons.
- An oxidizing agent is a substance that accepts electrons and is reduced in the process. It usually has a higher oxidation state and can easily gain electrons.

### Step 2: Identify the Elements in the Options
- The elements provided in the options are likely lanthanides, which include serium (Ce), terbium (Tb), and europium (Eu).

### Step 3: Determine the Common Oxidation States of Lanthanides
- The most stable oxidation state for lanthanides is +3.
- Europium can exist in two oxidation states: +2 and +3.
- Cerium can also exist in +3 and +4 oxidation states, while terbium primarily exists in the +3 state.

### Step 4: Analyze the Reducing and Oxidizing Properties
- **Europium (Eu)**:
- In its +2 state, europium can easily oxidize to +3, making it a strong reducing agent.
- **Serium (Ce)**:
- In its +3 state, cerium can be reduced to a lower oxidation state, making it a strong oxidizing agent.

### Step 5: Conclusion
- Based on the analysis, europium in the +2 state acts as a strong reducing agent, while cerium in the +3 state acts as a strong oxidizing agent.

### Final Answer
The strong reducing and oxidizing agents among the given options are:
- Strong Reducing Agent: Europium (Eu) in +2 state
- Strong Oxidizing Agent: Cerium (Ce) in +3 state