Which of the following gases is adsorbed most by activated charcoal?

Options

A. HCl
B. `NH_(3)`
C. `O_(2)`
D. `CO_(2)`

Explanation

To determine which gas is adsorbed most by activated charcoal, we can follow these steps:

### Step 1: Understand Adsorption
Adsorption is the process by which molecules from a gas or liquid adhere to a solid surface. Activated charcoal has a high surface area and is effective at adsorbing various gases.

### Step 2: Identify the Types of Gases
We need to consider the types of gases typically involved in adsorption:
- **Liquefiable gases**: These are gases that can easily be converted into a liquid state under pressure or at low temperatures (e.g., CO2, NH3).
- **Permanent gases**: These gases do not liquefy easily and remain in the gaseous state under standard conditions (e.g., O2, N2, He).

### Step 3: Compare the Options
If the question provides specific gases, we would compare their ability to be adsorbed by activated charcoal. Generally, liquefiable gases are adsorbed more effectively than permanent gases.

### Step 4: Conclusion
Based on the understanding that more readily liquefiable gases are adsorbed more than permanent gases, we conclude that among the options, O2 is the gas that is adsorbed most by activated charcoal.

### Final Answer
The gas that is adsorbed most by activated charcoal is **O2**.

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