Solutions – Chapter 2 CBSE Class 12 Chemistry
Case-based Questions
Read the given passages and answer the questions that follow:
A solution which obeys Raoult’s law strictly is called an ideal solution, while a solution which shows deviations from Raoult’s law is called a non-ideal solution or real solution. Suppose the molecules of the solvent and solute are represented by A and B respectively, and let gAB, gAA and gBB are the attractive forces between A—B, A—A and B—B respectively. An ideal solution of the components A and B is defined as the solution in which the intermolecular interactions between the components A—B are of the same magnitude as the intermolecular interactions found in the pure components A—A and B—B. Similarly, a non- ideal solution of the components A and B is defined as the solution in which the intermolecular interactions between the components A—B are of the different magnitude as the intermolecular interactions found in the pure components A—A and B—B.
1. What type of liquids form the ideal solution?
Ans. Liquids that have similar structures and polarities form ideal solutions.
2. Give one example of an ideal solution.
Ans. Benzene + Toluene
3. Write two characteristics of non-ideal solution.
4. On mixing liquid A and liquid B, volume of the resulting solution decreases, what type of deviation from Raoult’s law is shown by?
Ans. The solution will show negative deviation from Raoult’s law.
5. Which type of deviation will be shown by the solution, if yAB < yAA.
Ans. Solution will show positive deviation.