henry's law and raoult's law

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Jul 8, 2008
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ok EK says that henry's law is more accurate for the vapor partial pressure of a volatile solute where the solute has a low concentration.

Raoult's law is more accurate when looking at the vapor partial pressure of a solvent with high concentration.

doesn't a high solvent concentration automatically mean a low solute concentration?

It goes on to say: "one way to remember this is when the solvent concentration is high, each solvent molecule is surrounded by other solvent molecules, so it behaves more like a pure solvent. Thus the solvent vapor partial pressure is proportional to it's vapor pressure as a pure liquid; Raoult's law. When the volatile solute concentration is low, each molecule is surrounded by solvent molecules creating a deviation from the behavior of the pure volatile solute. Thus its vapor partial pressure is not proportional to its pressure as a pure substance (Raoult's law doesn't work in this case.), but is proportional to some constant; henry's law"

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