Which one of the following is incorrect for ideal solution ?
- $\Delta H_{mix} = 0 $
- $\Delta U_{mix} = 0 $
- $\Delta P = P_{obs} - P_{calculated \,by\, Raoult?? \,law} = 0 $
- $\Delta G_{mix} = 0$
The Correct Option is D
Solution and Explanation
Answer: Option 4: ΔGmix = 0
Explanation:
In an ideal solution:
- ΔHmix = 0 → No enthalpy change occurs during mixing.
- ΔUmix = 0 → Internal energy change upon mixing is zero.
- ΔP = Pobs − Pcalculated by Raoult’s law = 0 → Ideal solutions obey Raoult's Law throughout the composition range.
However,
- ΔGmix ≠ 0 — This is the incorrect statement.
- Even in an ideal solution, mixing leads to an increase in entropy (ΔSmix > 0), so the Gibbs free energy of mixing decreases (ΔGmix < 0).
Therefore, ΔGmix = 0 is incorrect for an ideal solution.
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Concepts Used:
Solutions
A solution is a homogeneous mixture of two or more components in which the particle size is smaller than 1 nm.
For example, salt and sugar is a good illustration of a solution. A solution can be categorized into several components.
Types of Solutions:
The solutions can be classified into three types:
- Solid Solutions - In these solutions, the solvent is in a Solid-state.
- Liquid Solutions- In these solutions, the solvent is in a Liquid state.
- Gaseous Solutions - In these solutions, the solvent is in a Gaseous state.
On the basis of the amount of solute dissolved in a solvent, solutions are divided into the following types:
- Unsaturated Solution- A solution in which more solute can be dissolved without raising the temperature of the solution is known as an unsaturated solution.
- Saturated Solution- A solution in which no solute can be dissolved after reaching a certain amount of temperature is known as an unsaturated saturated solution.
- Supersaturated Solution- A solution that contains more solute than the maximum amount at a certain temperature is known as a supersaturated solution.