PHYSICS · Multi-part · Fermi University Physics · Thermal, Statistical & Complex Systems · Kinetic theory and transport in gases · Kinetic theory and transport in gases
Thermal Physics, Ch Temperature, pressure and the kinetic theory of gases
Problem
A sealed rigid flask holds 0.50mol of methane, molar mass M=16.0gmol−1, at 300K. The methane molecule is not linear, so it has three rotational quadratic degrees of freedom as well as its three translations; its vibrations may be taken as inactive at this temperature. Treat the gas as dilute and ideal and take equipartition of energy to hold for the active degrees of freedom.
((a)) Find the root-mean-square speed of a methane molecule at 300K.
((b)) Find the energy that must be delivered to the flask's contents at fixed volume to raise their temperature by 20K. Use kB=1.381×10−23JK−1, NA=6.022×1023mol−1 and R=8.314JK−1mol−1.