Partial Pressure

Electrode Potential Calculation for Hydrogen

The given reaction for the hydrogen electrode is:

The Nernst equation for this half-reaction is:

If the logarithmic term equals zero, we get:

This leads to:

So, we have:

For Pure Water:

In pure water, the concentration of is . Therefore:

Conclusion:

The partial pressure of hydrogen gas ( ) in pure water is .

Partial Pressure of Oxygen in Alveoli and Blood

The partial pressure of oxygen ( ) in the alveoli of the lungs is less than that in oxygenated blood. In normal conditions, the in the alveoli is about 104 mmHg, while the in oxygenated blood is approximately 95 mmHg.

Alveolar Oxygen Partial Pressure:

The partial pressure of oxygen in the alveolar air is 104 mmHg. This refers to the oxygen pressure in the air present within the alveoli of the lungs. This pressure is the average in the alveoli where oxygen is exchanged with carbon dioxide during respiration.

Variation in Partial Pressure:

The partial pressure of oxygen in the alveoli can vary depending on factors such as changes in altitude and specific conditions (e.g., respiratory diseases, lung function, or atmospheric conditions).