Henry's Law Gas Solubility Calculator
Calculate gas solubility in liquid using Henry's Law C = KH × P.
Find dissolved gas concentration for O2, CO2, N2, and more at different pressures.
Henry’s Law states that the amount of gas dissolved in a liquid is proportional to the partial pressure of that gas above the liquid.
Formula:
C = KH × P
Where:
- C = concentration of dissolved gas (mol/L)
- KH = Henry’s law constant (mol/L/atm)
- P = partial pressure of gas (atm)
Henry’s Law constants at 25°C in water:
| Gas | KH (mol/L/atm) | Application |
|---|---|---|
| O₂ | 1.3 × 10⁻³ | Aquatic life, blood oxygen |
| CO₂ | 3.4 × 10⁻² | Carbonated beverages, blood pH |
| N₂ | 6.1 × 10⁻⁴ | Decompression sickness |
| H₂ | 7.8 × 10⁻⁴ | Fuel cells |
| CO | 9.5 × 10⁻⁴ | Toxic gas inhalation |
| CH₄ | 1.4 × 10⁻³ | Natural gas in water |
Important note: KH decreases as temperature increases — gases become less soluble when heated. This is why opening a warm soda releases more CO₂ than a cold one.
Carbonated beverages: Soda is carbonated at high pressure (≈ 3–4 atm CO₂). At atmospheric pressure (1 atm), CO₂ solubility drops and the gas escapes as bubbles.
C_CO2 at 4 atm = 3.4 × 10⁻² × 4 = 0.136 mol/L
Decompression sickness (the bends): Deep-sea divers breathe compressed air at high pressure, dissolving extra N₂ in blood. If they ascend too quickly, the N₂ comes out of solution as bubbles — like a shaken soda. Slow ascent (decompression stops) allows N₂ to escape safely through the lungs.
Dalton’s Law: In a gas mixture, each gas exerts its own partial pressure independently. P_O₂ in air at 1 atm = 0.209 atm (21% O₂).