Which of the following statements is NOT true about the ideal...

For an ideal solution, the following conditions hold true:

1. It obeys Raoult's law over the entire range of concentration.

2. The enthalpy of mixing is zero, i.e., $\Delta H_{mix} = 0$. No heat is evolved or absorbed.

3. The volume of mixing is zero, i.e., $\Delta V_{mix} = 0$.

4. The total vapor pressure of the solution is given by $P_{total} = P_A^{0} x_{A} + P_B^{0} x_{B}$. Since $x_{A} + x_{B} = 1$, the total vapor pressure is a weighted average of the vapor pressures of the pure components. Therefore, the vapor pressure of an ideal solution always lies between the vapor pressures of the pure components. It cannot be higher or lower than both.

Thus, the statement that the vapor pressure of the ideal solution can be higher or lower than those of pure components is incorrect.

Answer: The vapor pressure of the ideal solution can be higher or lower than those of pure components