Investigation of the Phase Transition Kinetics Liquid ⇌ Vapour by a Pressure‐jump Relaxation Technique

Abstract

The construction and performance of an apparatus for the kinetic study of mass transfer processes between gaseous and condensed phases is described. In this method, phase equilibrium is suddenly disturbed by the generation of a pressure jump in the gaseous phase after which the establishment of the new equilibrium state is followed by a sensitive pressure gauge. The application of the method to the kinetics of evaporation and condensation of liquids is described. For water at 20.0-C the evaporation coefficient is found to be a = 1.00 0.03, and the condensation coefficient a, = 0.98 f 0.06?. This is the first unambiguous proof that for resting water a = a, = 1.Es wird uber den Aufbau und die Arbeitsweise einer Apparatur zur Messung der Kinetik von Phasenubergangsprozessen zwischen gasformigen und kondensierten Phasen berichtet. Bei dieser Methode wird das Phasengleichgewicht durch einen Drucksprung in der Gasphase gestort und die Einstellungsgeschwindigkeit des neuen Gleichgewichtszustandes mit einem empfindlichen DruckmeDgerat verfolgt. Die Anwendung der Methode auf die Kinetik der Verdampfung und Kondensation von Fliissigkeiten wird beschrieben. Fur Wasser von 20,O 'C wird der Verdampfungskoeffzient zu a: = 1, OO f 0,03, und der Kondensationskoeffizient zu a, = 0,98 f 0,06, bestimmt. Dies ist der erste unzweifelhafte Nachweis, daB fur ruhendes Wasser gilt u = a, = 1.

Effect of HNO3 and HCl on D2O Desorption Kinetics from Crystalline D2O Ice

“…The experimentally measured evaporation rate, E exp , is related to the maximum theoretical evaporation rate by E exp = γ E max , where γ represents the evaporation coefficient. Measured evaporation coefficients for H 2 O ice have been reported to vary from γ = 0.006 to γ = 1.0 using a variety of experimental techniques. ,− Despite the variation in the measured values for the evaporation coefficient, γ is generally assumed to be unity. − …”

“…Measured evaporation coefficients for H 2 O ice have been reported to vary from γ ) 0.006 to γ ) 1.0 using a variety of experimental techniques. 34,[96][97][98][99] Despite the variation in the measured values for the evaporation coefficient, γ is generally assumed to be unity. [98][99][100][101][102][103][104][105] By using γ ) 1.0, E max in eq 1 can be replaced by the measured zero-order desorption rate.…”

H2O Condensation Coefficient and Refractive Index for Vapor-Deposited Ice from Molecular Beam and Optical Interference Measurements

“…The condensation coefficient, α, of H 2 O on ice has been the focus of numerous investigations. − The experimental values for the condensation coefficient have ranged from approximately α = 0.01 2-4 to α = 1.0. − Early investigations measured a variety of values for H 2 O evaporation from both liquid and ice surfaces and assumed that the condensation coefficient was equivalent to the evaporation coefficient. − ,− Direct measurements of the condensation coefficient 1,6-8,11,16-20 have not provided more consistent results and reported values have ranged from α = 0.026 11 to α = 1.0. ,, …”

“…[5][6][7] Early investigations measured a variety of values for H 2 O evaporation from both liquid and ice surfaces and assumed that the condensation coefficient was equivalent to the evaporation coefficient. [2][3][4][5][9][10][11][12][13][14][15] Direct measurements of the condensation coefficient 1,[6][7][8]11,[16][17][18][19][20] have not provided more consistent results and reported values have ranged from R ) 0.026 11 to R ) 1.0. 1,7,8 Accurate measurement of the H 2 O condensation coefficient on ice multilayers is very important to models of heterogeneous atmospheric chemistry.…”

Growth Kinetics of Ice Single Crystal from Vapour Phase and Variation of its Growth Form

“…The condensation rate is given by the Hertz-Knudsen equation; where p is the actual pressure of water vapour, p(*) the equilibrium vapour pressure of a quasi liquid layer of thickness * given by the following equation (4.2), Vm the molecular volume and * the condensation coefficient. Using pressure jump relaxation method, Schulze and Cammenga (1980) have shown that *=1 for water at 20*. Ria is a decreasing function of *, because p(*) is increasing function of * (Fig.…”