A rigid, insulated container holds an equimolar mixture of argon gas (molar mass =…
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A rigid, insulated container holds an equimolar mixture of argon gas (molar mass = 39.95 g·mol⁻¹) and neon gas (molar mass = 20.18 g·mol⁻¹) at 298 K. The gases do not react.
Respond to the following prompts about the microscopic motion of the particles in the container.
(a) Describe and compare the locations of the peaks of the speed distributions (Maxwell–Boltzmann curves) for argon and neon at 298 K.
(b) Using an energy–temperature argument, explain why the average kinetic energies of an argon atom and a neon atom are the same even though their molar masses differ.
(c) Is it possible for an argon atom in this sample to be moving faster than a neon atom at the same instant? Provide a reasoned explanation that refers to the shapes (tails) of the respective speed distributions.