For a diatomic gas with all vibrational modes excited, the molar specific heat at constant volume is:
A$(3/2)R$
B$(5/2)R$
C$(7/2)R$
D$R$
Answer & Solution
Correct answer: C. $(7/2)R$
DOF: 3 trans + 2 rot + 2 vib (KE+PE) = 7. $C_V = (7/2)R$. $C_P = (9/2)R$. $\gamma = 9/7 \approx 1.29$. (At room temperature, vibrations are typically frozen out.)
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?