Question

State Raoult’s law for the solution containing volatile components. What is the similarity between Raoult’s law and Henry’s law?

Answer 1

Hint: At first think about the definition of Raoult’s law and Henry’s law and where these laws are being used. Raoult’s law and Henry’s law describe the partial pressure of the chemical compounds.

Complete step by step answer:
Raoult’s law states that the partial pressure of each component of an ideal mixture of liquids is equal to the vapour pressure of the pure component multiplied by its mole fraction in the mixture. The relative lowering of vapour pressure of a dilute solution of nonvolatile solute is equal to the mole fraction of solute in the solution.
Mathematically, Raoult’s law for a single component in a ideal solution is stated as
\[{P_T} = {P_A}{x_A}\]
Where, ${P_T}$ is the partial pressure of the component A in gaseous mixture, ${P_A}$ is the equilibrium vapour pressure of component A, ${x_A}$ is the mole fraction of the component A in the mixture.
Henry’s law is a gas law that states that the amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid. The proportionality factor is called Henry’s law constant.
The similarity between the Raoult’s law and Henry’s law is that both laws state that the partial pressure of the volatile component is directly proportional to its mole fraction in the solution. In case of Raoults’s law it is a liquid and in case of Henry’s law it is a gas.
Note:
Raoult’s law and Henry’s law, both are applicable to volatile components of a solution. Henry’s law is a special case of Raoult's law. Raoult’s law does not at all account for the vapour pressure of the solute at low concentration.