Speed of sound in hydrogen isotopes derived from the experimental pvt data and an improved quantum law of corresponding state

The speed of sound in hydrogen isotopes can be applied to accurately determine the density, virial coefficient and equation of state. The functional relation between the speed of sound in a real gas and the experimental PVT data is derived from the virial equation of states. Utilizing the relation, the speed of sound in n-H(2) is calculated from the experimental PVT data available. The calculated results illustrate that the presented method has an accuracy of better than 0.25% within the pressure range of below 1500 atm. However, there is little experimental PVT data available for n-T(2), therefore, an improved quantum law of corresponding state (IQLCS) method, which is based on the physical nature that the different virial coefficients represent the interaction between the different number of molecules, is proposed for obtaining the speed of sound in n-T(2). Utilizing the IQLCS method, the speed of sound in n-T(2) can be obtained from the available speed of sound data in n-H(2) or n-D(2) via scaling the corresponding fitting coefficients at same temperature and pressure. The simulated results demonstrate that the IQLCS method is more accurate than the classical law of corresponding state(CLCS) and the maximum deviation is about 0.52% over the pressure range of below 1500 atm.