When climbers reach the summit of Mount Everest, they often rely on supplemental oxygen to enhance the amount of oxygen they can inhale. Understanding the relationship between oxygen concentration, atmospheric pressure, and partial pressure is crucial in this context. The partial pressure of a gas is calculated using Dalton's Law of Partial Pressures, which states that the partial pressure of a gas in a mixture is equal to the total pressure multiplied by the fraction of that gas in the mixture.
At sea level, the concentration of oxygen is approximately 20.9%, and the total atmospheric pressure is 760 mmHg. To find the partial pressure of oxygen at sea level, the calculation is as follows:
Partial Pressure of O2 = Concentration of O2 × Total Atmospheric Pressure
Using the values:
Partial Pressure of O2 = 0.209 × 760 mmHg = 159 mmHg.
For climbers using supplemental oxygen on Everest, the concentration can be as high as 50%, but the total atmospheric pressure drops significantly to 235 mmHg. The calculation for the partial pressure in this scenario is:
Partial Pressure of O2 = 0.5 × 235 mmHg = 117.5 mmHg.
In contrast, without supplemental oxygen at Everest, the concentration remains at 20.9%, but the total atmospheric pressure is still 235 mmHg. Thus, the partial pressure is calculated as:
Partial Pressure of O2 = 0.209 × 235 mmHg = 49 mmHg.
Summarizing the results, the partial pressures of oxygen are 159 mmHg at sea level, 117.5 mmHg with supplemental oxygen on Everest, and 49 mmHg without supplemental oxygen. To determine under which conditions the amount of oxygen dissolved in the blood would be most similar, we compare the partial pressures. The closest values are 117.5 mmHg and 49 mmHg, indicating that the oxygen dissolved in the blood at sea level and with supplemental oxygen would be most comparable.
To predict how much oxygen would dissolve in the blood, Henry's Law is applied. This law states that the amount of gas that dissolves in a liquid is proportional to the partial pressure of that gas above the liquid. Thus, the amount of oxygen dissolved in the blood is directly related to the partial pressures calculated earlier.
In summary, understanding Dalton's Law and Henry's Law is essential for comprehending how oxygen behaves under different atmospheric conditions, especially in extreme environments like Mount Everest. These principles highlight the importance of supplemental oxygen for climbers, ensuring they can maintain adequate oxygen levels despite the challenging conditions.