IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ethene with 2-Methylpropane (isobutane)

Components:
   (1) Ethene; C2H4; [74-85-1]  NIST Chemistry WebBook for detail
   (2) 2-Methylpropane (isobutane); C4H10; [75-28-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Benedict, M.; Solomon, E.; Rubin, L.C., Ind. Eng. Chem. 1945, 37, 55-59.

Variables:
   Temperature = 310.93 K, 344.26 K
   Pressure = 310.93 K, 344.26 K

Prepared By:
   W. Hayduk

Experimental Remarks:

   This paper contains a listing of three-component phase equilibria for methane, ethene and 2-methylpropane at several temperatures and pressures. These have been compiled and may be found in the Methane volume. The data here are all that are available for the two-component system.

Experimental Data:   (Subscripts 1,2,3, ..., in column headings refer to components 1,2,3, ...)


t/°C	T/K	Pressure [MPa]	Pressure Note	Pressure [MPa]	Pressure Note	Mole Fraction (x₁)	x₁ Note	Mole Fraction of Gas (y₁)	y₁ Note
37.78	310.93	3.447	1	2.897	1 Partial Pressure	0.497	liquid	0.8405	Mole Fraction Gas
71.11	344.26	3.447	1	2.151	1 Partial Pressure	0.296	liquid	0.624	Mole Fraction Gas

Notes:
   ¹  Calculated by compiler; the partial pressure is based on the gas phase composition.

Method/Apparatus/Procedure:
   A steel cell is used for the solubility measurements. The solvent floats on mercury. The mercury is in contact with a free piston and weights for pressure measurement. Equilibration is aided by rocking the cell and contents. As the gas is slowly sampled, mercury flows into the cell to keep the pressure constant. When only liquid remains, the pressure is increased and a liquid sample is obtained. The gas phase densities and olefin content are determined for the samples at low pressure.

Source and Purity of Materials:
   1. Ethene, anesthesia grade, was obtained from Ohio Chemical. It was purified by flash distillation and estimated to have 0.5 mole & ethane.
   2. 2-Methylpropane of the CP grade was from Phillips Petroleum with a purity of 99.2%.

Estimated Errors:
   Solubility: δx₁/x₁ = ± 0.02 (compiler)
   Temperature: δT/K = ± 0.02 (compiler)
   Pressure: δP/P = ± 0.001