At equlibirium the rate of dissolutiono of a solid solute in a valatile liquid slvent is ……

Options

A. less than the rate of crystallisation
B. greater than the rate of crystallisation
C. equal to the rate of crystallisation
D. zero

Explanation

To solve the question, we need to understand the concepts of dissolution and crystallization, particularly at equilibrium.

### Step-by-Step Solution:

1. **Understanding Dissolution and Crystallization**:
- Dissolution is the process where a solid solute dissolves in a solvent to form a solution.
- Crystallization is the process where solute particles come together to form solid crystals from a solution.

2. **Equilibrium Concept**:
- At equilibrium, the rates of the forward and backward reactions are equal. In this context:
- The forward reaction is the dissolution of the solid solute (solid → ions in solution).
- The backward reaction is crystallization (ions in solution → solid).

3. **Rate of Reactions**:
- At equilibrium, the rate of dissolution (forward reaction) equals the rate of crystallization (backward reaction).
- This means that the amount of solute dissolving into the solution is equal to the amount of solute crystallizing out of the solution.

4. **Conclusion**:
- Therefore, at equilibrium, the rate of dissolution of a solid solute in a volatile liquid solvent is **equal to the rate of crystallization**.

5. **Final Answer**:
- The correct option is that the rate of dissolution is **equal to the rate of crystallization**.