Distinguish between ideal and non ideal solution class 12

Ideal and non ideal solutions are terms used in chemistry to describe how mixtures of substances behave. These two types of solutions differ in several key aspects, including their behavior under certain conditions and their adherence to the principles of Raoult’s law. Let’s explore the differences between ideal and non-ideal solutions:

Define the term ideal solution

1. Behavior: An ideal solution is a theoretical concept used to describe a solution in which the interactions between the molecules of the solute and solvent are identical (or very similar) to the interactions between like molecules (solute-solute or solvent-solvent interactions).
2. Raoult’s Law: Ideal solutions adhere perfectly to Raoult’s law, which states that the vapor pressure of each component in the solution is directly proportional to its mole fraction in the solution. In other words, the behavior of an ideal solution can be predicted accurately using Raoult’s law.
3. Enthalpy of Mixing: In ideal solutions, the enthalpy of mixing (the energy change associated with mixing solute and solvent) is close to zero. This means that there is no significant heat evolved or absorbed when the components mix.
4. Deviation from Ideal Behavior: Ideal solutions are often an idealization, and real-world solutions rarely exhibit truly ideal behavior. Deviations from Raoult’s law and non-zero enthalpies of mixing are common in real solutions.
5. Examples: While ideal solutions are theoretical, they can serve as good approximations for certain binary mixtures under specific conditions. For example, very dilute solutions of nonpolar gases like oxygen and nitrogen in one another are often considered ideal.

Non-Ideal Solution (Real Solution):

1. Behavior: Non-ideal solutions, also known as real solutions, are mixtures in which the interactions between solute and solvent molecules differ significantly from the interactions between like molecules (solute-solute or solvent-solvent interactions). These differences lead to deviations from ideal behavior.
2. Raoult’s Law: Non-ideal solutions do not conform to Raoult’s law. The vapor pressures of components in a non-ideal solution may deviate from the predictions of Raoult’s law, and the deviations can be positive or negative.
3. Enthalpy of Mixing: In non-ideal solutions, the enthalpy of mixing is typically non-zero. This means that when solute and solvent are mixed, there can be either heat evolved (exothermic) or absorbed (endothermic) due to the interactions between their molecules.
4. Deviation from Ideal Behavior: Non-ideal solutions exhibit deviations from ideal behavior, and these deviations can manifest in various ways. For example, some non-ideal solutions may exhibit positive deviations, where vapor pressures are higher than predicted. Others may show negative deviations, where vapor pressures are lower than predicted.
5. Examples: Non-ideal solutions are the norm rather than the exception in real-world chemical systems. Examples include solutions of polar and nonpolar substances, solutions containing large or complex molecules, or mixtures where strong intermolecular forces or chemical reactions between components occur.

In summary, the main difference between ideal and non-ideal solutions lies in how well they conform to Raoult’s law and how their interactions between solute and solvent molecules compare to interactions between like molecules. Ideal solutions are theoretical and follow Raoult’s law precisely, while non-ideal solutions deviate from Raoult’s law due to significant differences in intermolecular interactions. Non-ideal solutions are encountered frequently in practical chemistry.