The speed of sound in oxygen at S.T.P. will be approximately: (given, $$R=8.3 \mathrm{~JK}^{-1}, \gamma=1.4$$)

A gas mixture consists of 8 moles of argon and 6 moles of oxygen at temperature T. Neglecting all vibrational modes, the total internal energy of the system is:

The given figure represents two isobaric processes for the same mass of an ideal gas, then

The parameter that remains the same for molecules of all gases at a given temperature is :