The Molecular Volumes and Expansivities of Liquid Normal Hydrogen and Parahydrogen
| Autor: | F. G. Brickwedde, R. B. Scott |
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| Rok vydání: | 1937 |
| Předmět: | |
| Zdroj: | The Journal of Chemical Physics. 5:736-744 |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.1750109 |
| Popis: | The molecular volumes at saturation of liquid normal hydrogen and parahydrogen between 14° and 20.4°K were measured with a fused quartz dilatometer, the amount of hydrogen being determined from the pressure of the gas in a calibrated flask at a measured temperature. The results are represented by the equations: V(n−H2) cm3mole−1=24.747–0.08005T+0.012716T2,V(p−H2) cm3mole−1=24.902–0.0888T+0.013104T2. At the normal boiling point of n‐H2(20.38°K), V(n‐H2)=28.397±0.010 and ΔV(p‐n)=0.138±0.010. The expansivity of p‐H2 is only slightly greater than that of n‐H2. The change observed in the molecular volumes of H2 in passing from the state in which the molecules rotate (o‐H2) to the state in which they do not rotate (p‐H2) is opposite in direction to the change observed in other substances when passing between these two states of molecular rotation and nonrotation. The changes in ``lattice'' energies are also of opposite sign. It is shown that the random state of orientation of the axes of p‐H2 molecules makes th... |
| Databáze: | OpenAIRE |
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