Which of the following statements is/ are correct? (A) For an ideal solution, the enthalpy and volume of mixing of pure components are zero. Choose the correct answer from the options given below: |
(C) and (D) only (A), (B) and (D) only (A) and (C) only (B), (C) and (D) only |
(A) and (C) only |
The correct answer is Option (3) → (A) and (C) only (A) For an ideal solution, the enthalpy and volume of mixing of pure components are zero: This is correct. In an ideal solution, the total volume is simply the sum of the volumes of the individual components ($\Delta V_{mix} = 0$), and no heat is absorbed or released during the mixing process ($\Delta H_{mix} = 0$). (B) The inter-molecular attractive forces between A-A and B-B are greater than those between A-B...: This is incorrect. This condition describes a non-ideal solution with a positive deviation from Raoult's law (like ethanol and cyclohexane), where the components prefer their own company over mixing. (C) The inter-molecular attractive forces between A-A and B-B are of the same order as those between A-B...: This is correct. This is the fundamental molecular requirement for an ideal solution. Because the $A-B$ interactions are essentially identical to the $A-A$ and $B-B$ interactions, there is no net energy change upon mixing. (D) For an ideal solution, the enthalpy and volume of mixing... are positive: This is incorrect. As stated in (A), these values must be zero. Positive values indicate a non-ideal solution with positive deviation. |