1. What is Partial Pressure of O2?

The partial pressure of oxygen (P_O2) is the pressure that oxygen would exert if it alone occupied the volume of the mixture at the same temperature. It's a key parameter in respiratory physiology and gas exchange calculations.

2. How Does the Calculator Work?

The calculator uses Dalton's Law of Partial Pressures:

Where:

• \( P_{O2} \) — Partial pressure of oxygen (atm)
• \( X_{O2} \) — Mole fraction of oxygen in the gas mixture (unitless)
• \( P_{total} \) — Total pressure of the gas mixture (atm)

Explanation: The partial pressure of a gas in a mixture is directly proportional to its mole fraction in that mixture.

3. Importance of Partial Pressure Calculation

Details: Partial pressure calculations are essential in respiratory medicine, diving physiology, anesthesia, and industrial gas applications. It helps determine oxygen availability for respiration and gas exchange.

4. Using the Calculator

Tips: Enter the mole fraction of oxygen (between 0 and 1) and the total pressure of the gas mixture in atmospheres. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the mole fraction of oxygen in normal air?
A: In dry air at sea level, the mole fraction of oxygen is approximately 0.2095.

Q2: How does altitude affect partial pressure of oxygen?
A: As altitude increases, total atmospheric pressure decreases, resulting in lower partial pressure of oxygen even though the mole fraction remains constant.

Q3: What is the normal partial pressure of oxygen in arterial blood?
A: Normally about 75-100 mmHg (0.099-0.132 atm) in healthy individuals at sea level.

Q4: Why is partial pressure important in diving?
A: Divers must monitor oxygen partial pressure to avoid oxygen toxicity at high pressures or hypoxia at low pressures.

Q5: How does this relate to Henry's Law?
A: The amount of oxygen dissolved in blood is directly proportional to its partial pressure in the alveolar gas (Henry's Law).