If diffusion capacity of `O_(2)` is 20 ml/min/Hg at rest, what will be diffusion capacity of `CO_(2)`

Options

A. 20
B. 200
C. 400
D. 20000

Answer

To determine the diffusion capacity of carbon dioxide (CO₂) when the diffusion capacity of oxygen (O₂) is given as 20 ml/min/Hg, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Data**:
- The diffusion capacity of O₂ is 20 ml/min/Hg at rest.

2. **Recognize the Factors Affecting Diffusion**:
- The diffusion of gases occurs through a pressure gradient.
- The solubility of the gases and the thickness of the membrane are also crucial factors.

3. **Compare the Solubility of O₂ and CO₂**:
- It is known that CO₂ is approximately 20 to 25 times more soluble in blood than O₂.

4. **Apply the Solubility Factor**:
- Since the solubility of CO₂ is much higher, we can infer that its diffusion capacity will also be higher under the same conditions (same pressure gradient and membrane thickness).

5. **Calculate the Diffusion Capacity of CO₂**:
- If the diffusion capacity of O₂ is 20 ml/min/Hg, then for CO₂, we multiply this value by the solubility factor (20 to 25 times).
- Using the lower estimate (20 times), we calculate:
\[ \text{Diffusion capacity of CO₂} = 20 \, \text{ml/min/Hg} \times 20 = 400 \, \text{ml/min/Hg} \]

6. **Conclusion**:
- Therefore, the diffusion capacity of CO₂ is 400 ml/min/Hg.

### Final Answer:
The diffusion capacity of CO₂ is **400 ml/min/Hg**.

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