Effect of vibrational excitation of molecules on the velocity of sound in a high-temperature diatomic gas

A formula for the velocity of sound, which is valid not only for barotropic gases, is derived on the basis of methods of the kinetic theory of gases. This formula is specified for various stages of relaxation of a high-temperature diatomic gas in the approximation of the model of anharmonic oscillators. A dependence between the populations of vibrational levels of molecules and the velocity of sound is found.