jp1c05996_si_002.pdf (114.04 kB)
Download file

Thermodynamics of Helium‑4 Dimerization and Trimerization

Download (114.04 kB)
journal contribution
posted on 12.10.2021, 12:41 by Arthur M. Halpern
A new equation of state (EOS) for helium-4 is used to obtain the equilibrium thermochemical properties of helium-4 dimerization (24He ⇌ 4He2) and trimerization (34He ⇌ 4He3) between 3.0 and 10.0 K. It is shown that at sufficiently low temperatures there are appreciable populations of dimer and trimer. The calculations account only for monomer, dimer, and trimer. At 3.0 K, the respective KPo values for dimerization and trimerization are 0.4832 and 0.4876, respectively. The standard enthalpy changes at 3.0 K are −54.53 and −110.0 J/mol, and standard entropy changes are −24.22 and −42.97 J/mol-K. Statistical thermodynamic calculations provide results that are qualitatively consistent with those obtained from the EOS calculations.