1,1,2,2-Tetrachloroethane

CAS RN:79-34-5

Volatilization

The Henry's Law constant for 1,1,2,2-tetrachloroethane is 4.2X10-4 atm-cu m/mole(1). This Henry's Law constant indicates that 1,1,2,2-tetrachloroethane is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec) (2) is estimated as 6.5 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 6 days(SRC). Laboratory measurements of the rate of evaporation of 1,1,2,2-tetrachloroethane from 5L of deionized water gave a half-life of 32-56 minutes(3). Other laboratory experiments report rapid volatilization from water (less than one hour) using stirring conditions(4). 1,1,2,2-Tetrachloroethane's Henry's Law constant indicates that volatilization from moist soil surfaces is expected to occur(SRC). 1,1,2,2-Tetrachloroethane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 5.74 mm Hg(5).
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