Question

Which of the following is not an example of an ideal solution?

• A. Benzene + Toluene
• B. n-Hexane + n-Heptane
• C. Ethyl alcohol + Water
• D. Ethyl bromide + Ethyl chloride

Hint:

Ideal solutions have similar intermolecular forces between the solute and solvent, with no heat or volume change during mixing. Non-ideal solutions like ethanol and water experience significant intermolecular interactions, leading to deviations.

Answer 1

The Correct Option is C

Step 1: Understanding Ideal Solutions
An ideal solution is one where the enthalpy of mixing is zero, and the intermolecular forces between the components are similar to those in the pure components.
In ideal solutions, the change in volume during mixing is also negligible.
Step 2: Analyzing the Given Options
Option (a) Benzene + Toluene and Option (b) n-Hexane + n-Heptane are examples of ideal solutions because their intermolecular forces are similar, and they form a solution with no significant heat or volume change.

Option (d) Ethyl bromide + Ethyl chloride is also an ideal solution because the intermolecular forces between these two substances are similar.
Step 3: Why Ethyl Alcohol + Water is Not Ideal
Ethyl alcohol and water do not form an ideal solution because their intermolecular forces are quite different.
Water forms hydrogen bonds, while ethanol also participates in hydrogen bonding but to a lesser extent.
This difference leads to an exothermic heat of mixing, making it a non-ideal solution.
Step 4: Conclusion Thus, ethyl alcohol and water are not an ideal solution.