A finely divided state of the catalyst is more efficient because in this state :

Options

A. It has larger activation energy
B. It can react with one of the reactants more efficiently
C. It has large surface area
D. All the above

Answer

To solve the question "A finely divided state of the catalyst is more efficient because in this state:", we will analyze the options provided and understand the concept of catalysts and their efficiency in different states.

### Step-by-Step Solution:

1. **Define Finely Divided State**:
- A finely divided state refers to a solid catalyst that is in a powdered or pellet form. This increases the surface area available for reactions.

2. **Understand the Role of a Catalyst**:
- A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. It facilitates the reaction by providing an alternative pathway with a lower activation energy.

3. **Importance of Surface Area**:
- The efficiency of a catalyst is significantly influenced by its surface area. A larger surface area allows more reactant molecules to interact with the catalyst simultaneously, leading to an increased rate of reaction.

4. **Evaluate the Options**:
- **Option 1**: "It has large activation energy."
- This is incorrect because a catalyst actually lowers the activation energy required for a reaction.
- **Option 2**: "It can react with one of the reactants more efficiently."
- This is also incorrect as catalysts do not react with reactants; they facilitate the reaction without being consumed.
- **Option 3**: "It has large surface area."
- This is correct because a finely divided catalyst indeed has a larger surface area, enhancing its efficiency.
- **Option 4**: "All of the above."
- This is incorrect since only option 3 is valid.

5. **Conclusion**:
- The correct answer is **Option 3: It has large surface area**. This is why a finely divided state of the catalyst is more efficient.

### Final Answer:
A finely divided state of the catalyst is more efficient because in this state it has a large surface area.