Hess's law is application for the determination of heat of

Options

A. transition
B. formation
C. reaction
D. all of these.

Answer

To solve the question regarding Hess's law and its application for the determination of heat, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Hess's Law**: Hess's law states that the total enthalpy change during a chemical reaction is the same, regardless of whether the reaction occurs in one step or multiple steps. This means that the heat absorbed or released (enthalpy change) can be calculated by summing the enthalpy changes of individual steps in the reaction.

2. **Identify the Options**: The question provides four options:
- Option 1: Transition
- Option 2: Formation
- Option 3: Reaction
- Option 4: All of these

3. **Analyze Each Option**:
- **Transition**: This refers to changes in states or phases (e.g., solid to liquid).
- **Formation**: This refers to the formation of compounds from their elements.
- **Reaction**: This is a general term that can encompass any chemical change.

4. **Determine the Correct Answer**: Since Hess's law applies to the calculation of enthalpy changes for various types of processes (including transitions, formations, and reactions), the most inclusive answer is:
- **Option 4: All of these**.

5. **Conclusion**: Hess's law can be applied to determine the heat of transition, formation, and reaction, making the correct answer "All of these".

### Final Answer:
Hess's law is applicable for the determination of heat of **all of these** (transition, formation, and reaction).

---