| Zugriffsnummer | 48192 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | The Lorentz-Lorenz function of five gaseous and liquid saturated hydrocarbons |
| Autor(in); Institution |
Hädrich, Jürgen; 7.22, Dichte und Grenzflächenenergie, PTB-Berlin
|
| Quelle/Jahr | Applied Physics:(1975), 7, 209 - 213 |
| ISSN | 0340-3793 |
| DOI | |
| Verlag | Berlin ; Heidelberg: Springer |
| Zusammenfassung | The refractive indices of compressed gaseous and liquid ethane, propane,n-butane,n-pentane, and liquidn-hexane were measured on up to seven isotherms at temperatures between 290 K and 500 K. Densities ranged from 0.2 g/cm3 to 0.7 g/cm3 at pressures up to 170 bar. The refractive index valuesn were combined with simultaneously measured density values ρ, to compute the Lorentz-Lorenz function LL =(n2-1)M/(n2+2) ρ=A n+Bn(ρ/M), whereM is the molar mass and A n and Bn are the first and second refractive index virial coefficients. Additionally, the functions LL/z (z=pV/nRT is the compressibility factor) of ethane, propane, and n-butane were computed to determine the second refractive index virial coefficientsB n(T). The relative uncertainty of the measured LL functions is 0.1% in most cases. At constant temperature (LL−A n)/An is ≦5·10−3 for ethane, propane, andn-butane and ≦0.02 for n-pentane and n-hexane. The greatest deviations of the LL functions from the A n value were measured at the temperatures near the critical points. The A n values show a temperature dependence which increases with increasing molar mass (maximum value: ΔA n/ΔT=0.0044 cm3/mol · K). The slopes of the LL-function become lower and the LL maxima become smaller with increasing distance of the temperature from the critical point. The B n values increase linearly with reciprocal temperature. |
