I am a physics student trying to calculate some values for a project I am working on, and am confused about Henry's constant.

I want to dissolve certain noble gases into freon in a pressurized chamber with temperature control, and want to know some of the numbers ahead of time.

I have seen the equation for the constant: $$K=\dfrac{p}{c}$$

My question is this: Where do the solvent characteristics come into play? I don't see how using this constant equation would get me a different constant for say, argon, in water vs. $\ce{C3F8}$?

  • 2
    $\begingroup$ Why, they come into play in that constant K. You switch to another solvent, you'll have another K. $\endgroup$ – Ivan Neretin May 20 '19 at 14:24
  • 1
    $\begingroup$ Also, $p$ is the partial pressure of the gas which is dissolving (which is distinct from the vapour of the liquid) and not the total pressure in the container. $\endgroup$ – Eashaan Godbole May 20 '19 at 14:25
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    $\begingroup$ To elaborate on another comment, it is better to write $K_{12}=p_2/c_2$ which makes explicit that K depends on the solute (subscript 2) and solvent (subscript 1) pair. $\endgroup$ – Buck Thorn May 20 '19 at 18:30
  • $\begingroup$ Thank you all for your input. As it turns out, Henry's Law seems to only be valid is the solvent is close to the density of water, so I will need to search for another method to solve this problem. $\endgroup$ – esteebo May 21 '19 at 12:05

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