For an ideal solution, the correct option is :

Question

Which one of the following is not correct for an ideal solution?

Answer 1

To solve this question, we need to understand the basic properties of an ideal solution. In thermodynamics, when we talk about mixing ideal substances at constant temperature $ T $ and pressure $ P $, certain properties are used to identify an ideal solution:

Enthalpy of mixing ($\Delta_{mix} H$): For an ideal solution, no heat is absorbed or evolved when the components are mixed. This implies that the interactions between like and unlike molecules are the same. Therefore, the enthalpy change for mixing is zero: $\Delta_{mix} H = 0$.
Gibbs Free Energy of mixing ($\Delta_{mix} G$): For mixing to be spontaneous, the Gibbs free energy should be negative, not zero. This is contrary to the option which says $\Delta_{mix} G = 0$.
Entropy of mixing ($\Delta_{mix} S$): The mixing of ideal solutions leads to an increase in entropy due to the increase in randomness. It cannot be zero as stated in the option $\Delta_{mix} S = 0$.
Volume of mixing ($\Delta_{mix} V$): In an ideal mixing process, there is no volume change upon mixing, implying $\Delta_{mix} V = 0$, but it cannot be non-zero as one option suggests.

Given these observations, the correct option is:

$\Delta_{mix}$ H = 0 at constant T and P

This conclusion is backed by the principles governing ideal solutions and their characteristics. Noticeably, options indicating zero change in Gibbs energy and entropy or non-zero volume changes do not align with the behavior of an ideal solution.

Answer 2

To solve this question, we need to understand the basic properties of an ideal solution. In thermodynamics, when we talk about mixing ideal substances at constant temperature $ T $ and pressure $ P $, certain properties are used to identify an ideal solution:

Enthalpy of mixing ($\Delta_{mix} H$): For an ideal solution, no heat is absorbed or evolved when the components are mixed. This implies that the interactions between like and unlike molecules are the same. Therefore, the enthalpy change for mixing is zero: $\Delta_{mix} H = 0$.
Gibbs Free Energy of mixing ($\Delta_{mix} G$): For mixing to be spontaneous, the Gibbs free energy should be negative, not zero. This is contrary to the option which says $\Delta_{mix} G = 0$.
Entropy of mixing ($\Delta_{mix} S$): The mixing of ideal solutions leads to an increase in entropy due to the increase in randomness. It cannot be zero as stated in the option $\Delta_{mix} S = 0$.
Volume of mixing ($\Delta_{mix} V$): In an ideal mixing process, there is no volume change upon mixing, implying $\Delta_{mix} V = 0$, but it cannot be non-zero as one option suggests.

Given these observations, the correct option is:

$\Delta_{mix}$ H = 0 at constant T and P

This conclusion is backed by the principles governing ideal solutions and their characteristics. Noticeably, options indicating zero change in Gibbs energy and entropy or non-zero volume changes do not align with the behavior of an ideal solution.

For an ideal solution, the correct option is :

The Correct Option is A

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