I am studying about binary solutions (with liquid solvents) and came across Henry's law. This is how it's stated in my textbook:

Henry's law states that at a constant temperature the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas present above the surface of the solution.

The way it's been stated does not say if the liquid solution is volatile or not.

So, while using this law, does it matter if the liquid solvent is volatile or non volatile?

  • $\begingroup$ The partial pressure is irrespective of any other component of the system in the gaseous phase. All we're doing is establishing that the equilibrium $\ce{A(g) <=> A(aq)}$ is a function only of temperature and the identify of $\ce{A}$. $\endgroup$ – Zhe May 13 '19 at 14:59
  • $\begingroup$ @Zhe so since the partial pressure is irrespective of any other component of the system thus it does not really matter if the solvent is volatile or not.? $\endgroup$ – Suzie Waters May 13 '19 at 17:19
  • $\begingroup$ That depends on what you mean by "does it matter?" It does not matter for the purposes of Henry's law, but that fixes the solvent. If the solvent is different, the constant of proportionality is different. So actually, my previous state is not as accurate as possible: given a fixed $\ce{A}$ and fixed solvent, the equilibrium is only a function of temperature. $\endgroup$ – Zhe May 13 '19 at 17:23
  • $\begingroup$ @Zhe actually i meant to ask the question for a fixed solute and solvent. i should have mentioned it in the question. $\endgroup$ – Suzie Waters May 13 '19 at 17:32
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    $\begingroup$ The main importance with Henry's law is that the solute be very dilute $\endgroup$ – B. Kelly May 14 '19 at 3:02

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