##### 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 g*AB*, g*AA *and g*BB *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 y_{AB} < **y

*.*_{AA}**Ans. Solution will show positive deviation.**