Which of the following is reversible process

Options

A. Melting of ice at `10^(@)C`
B. Mixing of two gases by diffusion
C. Evaporation of water at `100^(@)C` and 1 atm pressure
D. None of the above

Answer

To determine which of the following processes is reversible, we need to analyze each option based on the definition of a reversible process. A reversible process is one that can occur in both directions, meaning the system can return to its original state without any net change in the surroundings.

### Step-by-Step Solution:

1. **Option 1: Melting of Ice at 10 degrees Celsius**
- At 10 degrees Celsius, ice will melt into water. This process is not reversible at this temperature because once the ice melts, it cannot spontaneously return to ice without lowering the temperature to 0 degrees Celsius. Therefore, this process is irreversible at 10 degrees Celsius.
- **Conclusion:** This option is wrong.

2. **Option 2: Mixing of Two Gases by Diffusion**
- When two gases are mixed, they diffuse into each other. Once mixed, it is impossible to separate the gases back into their original states without external intervention. This process is not reversible because the mixed state cannot be returned to the original states without additional work.
- **Conclusion:** This option is also wrong.

3. **Option 3: Vaporization of Water at 100 degrees Celsius and Atmospheric Pressure**
- At 100 degrees Celsius and 1 atmospheric pressure, water can exist in both liquid and gas states. When water vaporizes, it can condense back into liquid water under the same conditions. This means that the process can occur in both directions, making it reversible.
- **Conclusion:** This option is correct.

### Final Answer:
The reversible process among the given options is **Option 3: Vaporization of Water at 100 degrees Celsius and Atmospheric Pressure**.

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