An airplane is pressurized to 650mmHg , which is the atmospheric pressure at a ski resort at 1.30×10^4 altitude.If air is 21 % oxygen, what is the partial pressure of oxygen on the plane?
About 650 mm x 0.21 = ??
To find the partial pressure of oxygen on the plane, we can use the concept of Dalton's law of partial pressures. According to Dalton's law, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each individual gas.
Step 1: Calculate the atmospheric pressure at sea level using the given altitude.
The atmospheric pressure decreases with increasing altitude. At sea level, the atmospheric pressure is typically around 760 mmHg. We can use this information to calculate the atmospheric pressure at the given altitude.
Given:
Atmospheric pressure at ski resort (sea level) = 760 mmHg
Altitude = 1.30×10^4 ft
The atmospheric pressure decreases by approximately 1 mmHg for every 31 ft of increase in altitude. Therefore, we can calculate the change in pressure due to the given altitude:
Change in pressure = (Altitude / 31 ft per mmHg)
= (1.30×10^4 ft) / (31 ft per mmHg)
≈ 419.35 mmHg
Now, we can find the atmospheric pressure at the given altitude:
Atmospheric pressure at altitude = Atmospheric pressure at sea level - Change in pressure
= 760 mmHg - 419.35 mmHg
≈ 340.65 mmHg
Step 2: Calculate the partial pressure of oxygen.
Given:
Total pressure inside the airplane = 650 mmHg
Percentage of oxygen in air = 21%
To find the partial pressure of oxygen, we need to calculate the percentage of oxygen in terms of a decimal, i.e., 21/100 = 0.21. Then, we can calculate the partial pressure of oxygen using the total pressure.
Partial pressure of oxygen = Percentage of oxygen × Total pressure
= 0.21 × 650 mmHg
≈ 136.50 mmHg
Therefore, the partial pressure of oxygen on the plane is approximately 136.50 mmHg.