Question

What is Raoult’s Law? Derive Raoult’s Law for solutions which contain non-volatile solute.

Answer 1

Hint: Raoult’s Law was named for the law of the French pharmacist François-Marie Raoult, who, while experimenting, discovered that the vapor pressure of the solution decreased simultaneously when substances were mixed in a solution. The law of Raoult was created in 1887 and is also considered the thermodynamic law.

Complete step by step solution:

Raoult’s Law states that a solution (or mixture) partial vapor pressure of a solvent is equal to or identical with a pure solvent vapor pressure multiplied in a solution by the mole fraction.
The equation of Raoult's law is written mathematically as;
Where, it is completely clear that-
Vapour pressure of the solution $\Rightarrow {P_{solution}} = {X_{solvent}}P_{solvent}^0$
Mole fraction of the solvent $= {X_{solvent}}$
Vapour pressure of the pure solvent $= P_{solvent}^0$
Raoult's Law is very similar to the ideal gas law, too. The sole exception to Raoult 's law is that alternatives are available. When you read about the ideal gas law, we know that the ideal behaviour of gasses is supposed to be zero or non-existent in intermolecular forces between dissimilar molecules. Raoult 's law, meanwhile, assumes that the intermolecular forces between different molecules are equal. Raoult's Law can also be used for non-ideal solutions. This is however achieved by integrating several factors in which the interactions between molecules of different substances must be taken into consideration.

Note: Some limitations of Raoult’s Law- The law of Raoult is suitable for ideal solutions. But ideal solutions are difficult to find and rare. Various chemicals must have the same chemical components. As many of the liquids in the mixture do not consist of the same attractive forces, such solutions tend to deviate from the law.