`V_(1)` mL of `SO_(2)`, filled in a tube at 1 atm between a movable frinctionless piston and a porous plug. The tube is left in air till the piston stops moving. The volume `V_(1)` is found to increase to `V_(2)`. The volume `V_(2)` contains

Options

A. air only
B. `SO_(2)` only
C. both air and `SO_(2)`
D. neither air nor `SO_(2)`

Answer

To solve the problem, we need to analyze the situation described in the question step by step.

### Step 1: Understanding the Initial Conditions
Initially, we have a volume \( V_1 \) of sulfur dioxide (\( SO_2 \)) gas in a tube at 1 atm pressure. The gas is contained between a movable frictionless piston and a porous plug.

**Hint:** Identify the initial state of the system and the properties of the gas involved.

### Step 2: Analyzing the Movement of the Piston
The tube is left in air, which means that the external pressure (atmospheric pressure) is acting on the piston. The piston will move until the internal pressure (pressure of the gas inside the tube) equals the external pressure.

**Hint:** Consider how the pressure equilibrium affects the movement of the piston.

### Step 3: Understanding the Role of the Porous Plug
The porous plug allows gas to escape from the tube. As the piston moves, the \( SO_2 \) gas can exit the tube through the porous plug, and air can enter the tube from the outside.

**Hint:** Think about the implications of having a porous plug in terms of gas exchange.

### Step 4: Final Condition of the System
Eventually, the piston stops moving when the internal pressure equals the external pressure. At this point, since the tube was left in air, the \( SO_2 \) gas has escaped through the porous plug, and the volume \( V_2 \) will now contain only air.

**Hint:** Reflect on what happens to the gas inside the tube when the system reaches equilibrium.

### Step 5: Conclusion
Since the \( SO_2 \) gas has escaped and the only gas remaining in the tube is air, the final volume \( V_2 \) contains air.

**Final Answer:** The volume \( V_2 \) contains air.

### Summary of Steps:
1. Identify the initial conditions of the gas.
2. Analyze how the piston moves in response to external pressure.
3. Consider the effect of the porous plug on gas exchange.
4. Determine the final state of the system when equilibrium is reached.
5. Conclude what the final volume contains.