1. Tardigrade
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  4. At ordinary temperature, 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 ( CV= molar heat capacity at constant volume)

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Q. At ordinary temperature, 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 ($ C_{V}=$ molar heat capacity at constant volume)

Punjab PMETPunjab PMET 2009Thermodynamics

Solution:

At ordinary temperature, the vibrational kinetic energy of a monoatomic gas is zero.
So, $C_{V}=\frac{3}{2}R$
The value is same for high temperature also.
In case of diatomic gas
$C_{V}=\frac{5}{2}R$ (at low temperature)
Also, $C_{V} >\frac{5}{2}R$ (at high temperature due to vibrational kinetic energy)