Dalton's Law of Partial Pressures
Dalton's Law states that the total pressure of a gas mixture equals the sum of the partial pressures of each component. The partial pressure of a gas is proportional to its mole fraction:
pᵢ = χᵢ × P_total
P_total = p₁ + p₂ + p₃ + ...
Applications
- Atmospheric chemistry: O₂ is 21% of air → pO₂ = 0.21 × 1 atm ≈ 0.21 atm
- Scuba diving: At depth, partial pressures increase — O₂ toxicity and N₂ narcosis become concerns
- Anesthesiology: Partial pressure of anesthetic agents determines their effect