How to Leverage off Henry’s Law to Get the Information You Are Looking for – Part 2

Henry's law, a gas law, states that the amount of dissolved gas in a liquid is directly proportional at equilibrium to its partial pressure above the liquid.

The depth-dependent dissolution of Oxygen and Nitrogen in the blood of underwater divers which changes during decompression, possibly causing decompression sickness if the decompression occurs too fast, is an application of Henry’s law.

Once the bottle of a carbonated soft drink is opened, almost pure Carbon dioxide above the liquid in the container at a pressure higher than the atmospheric pressure escapes decreasing the pressure above the liquid, resulting in fast degassing as the dissolved gas is liberated from the solution. This is an everyday example of Henry’s law.

Question:

K_H for the solubility of N₂ gas in water at 298 K is 1.0 × 10⁵ atm. 0.8 is the mole fraction of N₂ in the air. Calculate the moles of N₂ from the air dissolved in 10 moles of water at 298 K & 5 atm.

Solution: 

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p_N2 = Partial pressure of N₂, χ_N2 = Mole fraction of N₂ in the air, P_total = Total pressure, C = Solubility of a gas in a liquid

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References:

(1)    Wikipedia Contributors. Henry’s law. Wikipedia. https://en.wikipedia.org/wiki/Henry%27s_law.

‌‌(2)    Henry's Law