Volatility of chlorinated n -alkanes (C10–C12): Vapor pressures and Henry's law constants

Abstract

Polychlorinated n-decanes, n-undecanes, and n-dodecanes with chlorine numbers of two to six were utilized to assess physicochemical properties of short-chain (C10–C13) chlorinated paraffins. Subcooled-liquid vapor pressures (Ps), determined using the vapor pressure–gas-liquid chromatography correlation technique, ranged from 1.4 × 10−4 to 0.50 Pa at 25°C among the compounds studied. Vapor pressures tended to decrease with increasing carbon chain length and degree of chlorination according to the correlation: log P = −0.353(C No.) — 0.645(0 No.) + 4.462. Henry's law constants (Hs), determined using gas-sparging techniques, ranged from 17.7 to 0.68 PaṁmVmol for terra- and pentachloro congeners at 23°C. The Henry's law constants for 1,10-dichlorodecane and 1,12-dichlorododecane, 499 and 648 Paṁm3/mol respectively at 25°C, were calculated from experimentally determined vapor pressures and water solubilities. Henry's law constants decreased with increasing degree of chlorination.