Raoult’s Law and Henry’s Law

Roult’s Law ( Ω = 0 )

- the vapor pressure exerted by a component i in a solution is equal to the product of mole fraction of i in the solution and the saturated vapor pressure of pure liquid i at the temperature of the solution.

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Henry’s Law ( Ω < 0 )

- for dilute A-B solution(B>>A) and the Ω < 0, rate of evaporation r’_e(A) is independent of composition at small fraction of A

(r_e(A) is evaporation rate of pure, more precisely Ω = 0 )

At a constant temperature, the amount of a given gas dissolved in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid (Wikipedia)

ref. David R. Gaskell, “Chapter 9: The Behavior of Solutions”, in Introduction to the Thermodynamics of Materials 4th ed. Taylor & Francis, New York London, 2002, pp. 211-214