A sample of carbon dioxide is cooled until it begins to deviate markedly from the…
CHEMISTRY · Single correct · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A sample of carbon dioxide is cooled until it begins to deviate markedly from the ideal-gas law. Which of the following best explains why the deviation occurs at very low temperatures?
(a) Repulsive forces arising from the finite molecular volume become significant as the gas cools.
(b) Attractive intermolecular forces become significant compared with the molecules’ kinetic energy.
(c) The gas begins to condense, so the number of free molecules changes and the ideal-gas law no longer applies.
(d) Collisions between molecules lose kinetic energy and cease to be perfectly elastic, violating the kinetic-theory assumptions.