If vibrations are excited, a diatomic molecule has DOF:
A5
B6
C7 (3 trans + 2 rot + 2 vib (KE + PE))
D9
Answer & Solution
Correct answer: C. 7 (3 trans + 2 rot + 2 vib (KE + PE))
At high T, vibrational modes 'unlock' — diatomic vibration contributes 2 DOF (KE + PE both quadratic). Total = 3 + 2 + 2 = 7. $C_V = (7/2)R$. Realised only at high temperatures.
Related questions
Molecules in a gas move at speeds of the order of the speed of:Compared with solids, atoms in gases are much:The mean free path in gases is of the order of:Argon is an example of which kind of gas?A gas like argon has which kind of degrees of freedom only?Motion of a body as a whole from one point to another is called:A molecule confined to a plane has how many degrees of freedom?A molecule free to move in space needs how many coordinates?