When the common salt dissolves in water, the entropy of the system increases. This means that the sign of `Delta`S is ______ and randomness of the system _______

Options

A. Undetermined, increases
B. Positive, decreases
C. Positive, increases
D. Negative, decreases

Answer

To solve the question, we need to analyze the process of dissolving common salt (sodium chloride, NaCl) in water and its effect on entropy and randomness.

### Step-by-Step Solution:

1. **Understanding the Dissolution Process**:
- When common salt (NaCl) dissolves in water, it dissociates into its constituent ions: Na⁺ and Cl⁻. This process transforms the solid salt into ions that are dispersed in the liquid water.

2. **State of Matter Change**:
- The salt starts as a solid, where the ions are closely packed in a crystalline structure. Upon dissolving, these ions are released into the liquid phase, where they are more spread out and free to move.

3. **Entropy and Randomness**:
- Entropy (ΔS) is a measure of the disorder or randomness of a system. In this case, the transition from a solid state (low entropy, ordered structure) to a liquid state (high entropy, disordered structure) indicates an increase in randomness.

4. **Sign of Change in Entropy**:
- Since the randomness of the system increases when the salt dissolves, the change in entropy (ΔS) is positive. A positive ΔS indicates that the system has become more disordered.

5. **Conclusion**:
- Therefore, we conclude that the sign of ΔS is positive, and the randomness of the system increases.

### Final Answer:
The sign of ΔS is **positive** and the randomness of the system **increases**.