Which of the following conditions represents an equilibrium?

Options

A. Freezing of ice in an open vessel, temperature of ice is constant
B. Few drops of water are present along with air in a balloon, temperature of balloon is constant
C. Water is boiling in an open vessel over stove, temperature of water is kept constant
D. All the statements (1), (2) and (3) are correct for the equilibrium

Answer

To determine which of the given conditions represents an equilibrium, we need to analyze each option based on the definition of chemical equilibrium. Equilibrium is a state where the rate of the forward reaction equals the rate of the reverse reaction, and this can typically only be established in a closed system.

### Step-by-Step Solution:

1. **Understand the Concept of Equilibrium**:
- Equilibrium occurs when the concentrations of reactants and products remain constant over time. This is usually achieved in a closed system where no substances can enter or leave.

2. **Analyze Option A**:
- **Condition**: Freezing of ice in an open vessel with constant temperature.
- **Analysis**: This is an open system because the ice can lose heat to the surroundings, and water vapor can escape. Therefore, it does not represent equilibrium.
- **Conclusion**: Option A is incorrect.

3. **Analyze Option B**:
- **Condition**: Few drops of water are present along with air in a balloon with constant temperature.
- **Analysis**: Although the balloon is not completely closed, the presence of water and air can reach a state where the evaporation of water and condensation occurs at the same rate, suggesting a dynamic equilibrium can be established.
- **Conclusion**: Option B can represent equilibrium.

4. **Analyze Option C**:
- **Condition**: Water is boiling in an open vessel over a stove with constant temperature.
- **Analysis**: Boiling water in an open vessel allows steam to escape, preventing the establishment of equilibrium between the liquid and vapor phases.
- **Conclusion**: Option C is incorrect.

5. **Analyze Option D**:
- **Condition**: All statements A, B, and C are correct for equilibrium.
- **Analysis**: Since options A and C are incorrect, this option cannot be correct.
- **Conclusion**: Option D is incorrect.

6. **Final Conclusion**:
- The only option that can represent equilibrium is **Option B**.

### Final Answer:
**Option B** is the correct answer.

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