Answer to Question #108948 in Molecular Physics | Thermodynamics for Yossef

Question

If two moles of Nitrogen is heated from 20 to 30◦C, what are the changes in the translational, rotational and total internal energy?

Answer 1

As per the given question,

Total number of moles of the Nitrogen gas(n)=2

Initial temperature $(T_1)=20^\circ C=273+30=293K$

Final temperature $(T_2)=30^\circ C=303K$

Boltzmann constant $(k)=1.38\times 10^{-23}J/K$

$R=8.32 mol^{-1}k^{-1}$

Change in transnational $=\dfrac{3R(T_2-T_1)}{2}\times n$

$=3\times 8.32\times (303-293)=249.6J$

Change in rotational energy $=nRT$

$=2\times 8.31\times (303-293)=166.2J$

Change in internal energy=$249.6-166.2=83.4J$