A: `CuSO_4 5H_2O` is a solution of liquid in solid.
R: Solution is a homogeneous mixture.

Answer

To solve the assertion-reason question regarding `CuSO4·5H2O`, we will analyze both the assertion and the reason step by step.

### Step 1: Analyze the Assertion
The assertion states that `CuSO4·5H2O` is a solution of liquid in solid.

- **Understanding `CuSO4·5H2O`:** This compound is known as copper(II) sulfate pentahydrate. It consists of one copper(II) sulfate (CuSO4) molecule and five water (H2O) molecules.
- **Nature of the Mixture:** In this case, the water molecules are incorporated into the crystalline structure of the CuSO4 solid. The water acts as a solvent, and since it is part of the solid crystalline structure, we can classify this as a liquid in solid solution.

**Conclusion for Step 1:** The assertion is correct because `CuSO4·5H2O` indeed represents a solution of liquid (water) in solid (copper(II) sulfate).

### Step 2: Analyze the Reason
The reason states that a solution is a homogeneous mixture.

- **Definition of a Solution:** A solution is formed when a solute (in this case, CuSO4) is dissolved in a solvent (water).
- **Homogeneous Mixture:** In a homogeneous mixture, the components are uniformly distributed, and the mixture appears the same throughout. In the case of `CuSO4·5H2O`, the water molecules are uniformly integrated into the solid structure, making it a homogeneous mixture.

**Conclusion for Step 2:** The reason is also correct because solutions are indeed homogeneous mixtures where the solute and solvent are not distinguishable.

### Step 3: Relationship Between Assertion and Reason
While both the assertion and the reason are correct, the reason does not directly explain the assertion. The assertion specifically refers to the nature of `CuSO4·5H2O` as a liquid in solid solution, while the reason discusses the general property of solutions being homogeneous mixtures.

### Final Conclusion
- **Assertion (A):** Correct
- **Reason (R):** Correct
- **Explanation Relationship:** The reason is not the correct explanation of the assertion.