1. What is Partial Pressure?

Partial pressure is the pressure that a gas in a mixture of gases would exert if it occupied the entire volume alone at the same temperature. It's a key concept in gas laws and respiratory physiology.

2. Dalton's Law of Partial Pressures

The calculator uses Dalton's Law:

Where:

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

Explanation: The law states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.

3. Importance of Partial Pressure

Details: Partial pressure is crucial in respiratory physiology (oxygen and carbon dioxide exchange), industrial gas applications, and chemical reactions involving gases.

4. Using the Calculator

Tips: Enter mole fraction (between 0 and 1) and total pressure (must be positive). Select the appropriate pressure unit (atm or Pascal).

5. Frequently Asked Questions (FAQ)

Q1: What is mole fraction?
A: Mole fraction is the ratio of the number of moles of a particular gas to the total number of moles of all gases in the mixture.

Q2: What units can be used for pressure?
A: Common units are atmospheres (atm) or Pascals (Pa). 1 atm = 101325 Pa.

Q3: Does temperature affect partial pressure?
A: Yes, but only indirectly through its effect on total pressure (for a fixed volume) or mole fraction (if gas amounts change with temperature).

Q4: Can this be used for ideal gas mixtures only?
A: Dalton's Law applies exactly to ideal gas mixtures and is a good approximation for real gases at low pressures.

Q5: How is this related to Henry's Law?
A: Henry's Law relates the partial pressure of a gas above a liquid to its concentration in the liquid, making partial pressure calculations important for solubility.