Which of the following is NOT a postulate of the Kinetic Molecular Theory of gases (or is true only for ideal gases but not for real gases)?
Correct: B
Let's analyze the postulates:
A) Gas particles are in continuous, random motion: This is a fundamental postulate of KMT, applicable to both ideal and real gases.
B) The volume occupied by the gas molecules themselves is negligible compared to the total volume of the container: This is a key postulate specific to *ideal* gases. Real gas molecules do occupy a finite volume, which becomes significant at high pressures, causing deviation from ideal behavior.
C) The average kinetic energy of gas molecules is directly proportional to the absolute temperature: This is a fundamental postulate of KMT and holds true for both ideal and real gases.
D) Collisions between gas molecules are perfectly elastic, and there is no net loss of kinetic energy: This is also a fundamental postulate of KMT.
The question asks for a statement that is NOT a postulate *or* is true only for ideal gases. Option B falls into the latter category, as it is an ideal gas assumption that is not strictly true for real gases, especially under non-ideal conditions.