Medical College Admission Test (MCAT) General Chemistry Practice Exam

The statement that pressure and temperature can vary independently is incorrect regarding ideal gases. In the context of ideal gas behavior, there is a defined relationship between the pressure, volume, and temperature of a gas, as articulated by the ideal gas law (PV = nRT). In an isolated system, if the volume is held constant, changing the temperature of a gas will directly affect its pressure according to this relationship. Therefore, pressure and temperature do not vary independently under constant volume conditions. The other statements about ideal gases are accurate. Gas molecules indeed do not exert significant attractive or repulsive forces upon each other, meaning that intermolecular forces are negligible, which is foundational to the concept of an ideal gas. Additionally, the volume occupied by gas molecules themselves is typically much smaller compared to the volume of the container, which justifies the assumption that gas volumes are negligible when analyzing gas behavior. Finally, the principle that all collisions between gas molecules are elastic signifies that there is no net loss of kinetic energy in these collisions, an assumption consistent with ideal gas behavior.