Question

propane exists as a gas at standard pressure and temperature above -44°c; however, at high pressures or lower temperatures, propane exists as a liquid. which of the following postulates of the kinetic molecular theory of gases does propane contradict? a. molecules move in straight lines until they collide with the container or other molecules. b. interactions among molecules, with the exception of collisions, are negligible. c. the molecules of a gas are in constant, random motion. d. the average kinetic energy of the gas depends only on its temperature. 8. according to the kinetic molecular theory, the pressure of a gas increases as the number of moles of gas molecules increases because -- a. stronger intermolecular forces push the particles farther apart. b. stronger intermolecular forces are redirected to the walls of the container. c. more particles collide with the walls of the container. d. more particles occupy more space.

Explanation:

Question 1 (Which postulate is contradicted?)

The kinetic molecular theory (KMT) of gases has postulates. One postulate (B) states that intermolecular interactions (except collisions) are negligible. The given info says propane is gas at certain conditions but liquid at high pressure/low temp, meaning intermolecular forces (attractions) are significant here, contradicting postulate B. Postulates A, C, D don't relate to phase change due to intermolecular forces.

KMT: Pressure is due to molecule collisions with container walls. More moles mean more molecules. More molecules lead to more collisions with the walls, increasing pressure. Option A: Intermolecular forces in gases (KMT) are negligible, so no. Option B: Intermolecular forces aren't redirected to walls. Option D: In KMT, gas volume is mostly empty space; more moles don't mean more space occupied (volume of container is main, or volume adjusts, but pressure increase here is about collisions). So C is correct.

Answer:

B. Interactions among molecules, with the exception of collisions, are negligible

Question 2 (Pressure increase with moles)