At ordinary temperatures, the molecules of an ideal gas have only translational and rotational kinetic energies. At high temperatures, they may also have vibrational energy. As a result of this, at higher temperatures, molar specific heat capacity at constant volume, `C_(V)` is

Options

A. `gt5//2 R "for a diatomic gas"`
B. `gt 3//2 R "for a monoatomic gas"`
C. `lt 5//2 R "for a diatomic gas"`
D. `= 3//2 R "for a monoatomic gas"`

Answer

A

Explanation

For a monoatomic gas, vibrational K.E, is zero at all temperatre, so `C_(upsilon) = 3/2 R` for a monoatomic gas even at high temperature. In case of a diatomic gas, `C_(upsilon) = 5/2 R` at low temperature and `C_(upsilon) gt 5/2 R` at high temperature on account of vibrational K.E.