62Atmospheric pressure atop Mt. Everest is 3.30×104N/m2. (a) What is the partial pressure of oxygen there if it is 20.9% of the air? (b) What percent oxygen should a mountain climber breathe so that its partial pressure is the same as at sea level, where atmospheric pressure is 1.01×105N/m2? (c) One of the most severe problems for those climbing very high mountains is the extreme drying of breathing passages. Why does this drying occur?
(a) To find the partial pressure of oxygen atop Mt. Everest, we need to first calculate the atmospheric pressure due to all gases and then determine the partial pressure of oxygen based on its percentage in the air.
Given:
Atmospheric pressure atop Mt. Everest = 3.30×10^4 N/m^2
Percentage of oxygen in the air = 20.9%
Step 1: Calculate the partial pressure of oxygen
Partial pressure of oxygen = (Percentage of oxygen / 100) * Atmospheric pressure
Partial pressure of oxygen = (20.9 / 100) * 3.30×10^4 N/m^2
Now, you can calculate the answer by performing the multiplication.
(b) To find the percentage of oxygen that a mountain climber should breathe so that its partial pressure is the same as at sea level, we need to use the ratio of the partial pressures of oxygen at sea level and atop Mt. Everest.
Given:
Atmospheric pressure at sea level = 1.01×10^5 N/m^2
Partial pressure of oxygen atop Mt. Everest (calculated in part a)
Step 1: Calculate the percentage of oxygen to be breathed at Mt. Everest
Percentage of oxygen = (Partial pressure of oxygen atop Mt. Everest / Atmospheric pressure at sea level) * 100
Now, you can calculate the answer by performing the division and multiplication.
(c) The severe drying of breathing passages at high altitudes occurs due to the low humidity in the air. As climbers ascend to higher altitudes, the atmospheric pressure decreases and the air becomes thinner. Thinner air cannot hold as much moisture as denser air at lower altitudes, resulting in lower humidity levels.
When climbers breathe in the dry air at high altitudes, the moisture in their respiratory system (including nasal passages, throat, and lungs) gets evaporated quickly. This rapid evaporation leads to drying out of the respiratory passages, causing discomfort, irritation, and sometimes even nosebleeds. The dry air can also cause dehydration in the body.
To combat the drying effect, climbers often use breathing devices and hydrate themselves regularly to maintain their respiratory moisture levels.