Equal amounts (1.0 mol) of NH and CH are each placed in identical 5.0 L rigid…
CHEMISTRY · Single correct · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
Equal amounts (1.0 mol) of NH3 and CH4 are each placed in identical 5.0 L rigid containers at 273 K. Which statement best predicts how the measured pressures compare with the pressures calculated for ideal gases and explains the result?
(a) NH3 will exert a higher pressure than predicted, primarily because hydrogen bonding causes greater repulsion between molecules.
(b) Both gases will exert lower pressures than predicted, because attractive intermolecular forces dominate under these conditions for all gases.
(c) NH3 will exert a lower pressure than predicted, primarily because strong dipole–dipole (hydrogen-bond) attractions reduce the frequency and momentum of particle collisions with the walls.
(d) NH3 will exert a higher pressure than predicted, primarily because the finite volume of NH3 molecules significantly reduces the free space available for motion.