Assertion (A): An ideal solution obeys Henry's law.
Reason (R): In an ideal solution, solute-solute as well as solvent-solvent interactions are similar to solutesolventinteraction

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is True

Explanation

To analyze the given assertion and reason, we need to break down the concepts of ideal solutions, Henry's law, and Raoult's law.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "An ideal solution obeys Henry's law."
- **Henry's law** applies to dilute solutions and states that the amount of gas that dissolves in a liquid is proportional to the partial pressure of that gas above the liquid. This law is typically applicable to gases dissolved in liquids, not ideal solutions in general.

2. **Understanding the Reason (R)**:
- The reason states that "In an ideal solution, solute-solute as well as solvent-solvent interactions are similar to solute-solvent interactions."
- This is a correct statement. In an ideal solution, the interactions between the different types of molecules (solute-solute, solvent-solvent, and solute-solvent) are similar, which is a key characteristic of ideal solutions.

3. **Evaluating the Truth of the Assertion and Reason**:
- Since the assertion is false (ideal solutions follow Raoult's law, not Henry's law), and the reason is true (the interactions are similar), we can conclude that:
- Assertion (A) is false.
- Reason (R) is true.

4. **Conclusion**:
- Based on the analysis, the correct answer is that the assertion is false while the reason is true. Therefore, the answer is option 4.