Diffusion coefficients for MgCl/sub 2/--H/sub 2/O and the sea water analog MgCl/sub 2/(0. 05M)--NaCl(0. 5M)--H/sub 2/O at 25/sup 0/C

Conference · Wed Dec 01 00:00:00 EST 1976 · EOS, Trans., Am. Geophys. Union; (United States)

OSTI ID:5384225

Miller, D G; Eppstein, L B

Diffusion in multicomponent systems is important in understanding transport in and out of ocean sediments and transport of brines through deep sedimentary sequences. Diffusion data are presented for the ternary seawater analog MgCl/sub 2/(0.05M)-NaCl(0.5M)-H/sub 2/O at the seawater composition. The values of D/sub 11/, D/sub 12/, D/sub 21/, D/sub 22/ are 0.730 x 10/sup -5/, 0.015 x 10/sup -5/, 0.756 x 10/sup -5/, 1.443 x 10/sup -5/ cm/sup 2//sec, respectively, where 1 denotes MgCl/sub 2/, 2 denotes NaCl. Note that the cross term D/sub 21/ is larger than D/sub 11/. This means a gradient of MgCl/sub 2/ induces a larger flow of NaCl than of MgCl/sub 2/. Thus, the common assumption of zero cross terms can be a serious error. Also presented are data for MgCl/sub 2/-H/sub 2/O from 0.02 molar to 5 molar (near saturation). All diffusion data were obtained optically by Rayleigh interferometry. The ternary results are the first to be obtained from Rayleigh fringe patterns. The ternary diffusion coefficients together with existing activity coefficient data show that the Onsager Reciprocal Relations for diffusion are satisfied within the estimated experimental error. Because multicomponent experiments are difficult, estimation procedures for diffusion coefficients are important. The present data will contribute to extension of these procedures.

• Research Organization: Univ. of California, Livermore
• OSTI ID: 5384225
• Journal Information: EOS, Trans., Am. Geophys. Union; (United States), Vol. 57:12; Conference: AGU fall annual meeting, San Francisco, CA, USA, 6 Dec 1976
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
MAGNESIUM CHLORIDES
DIFFUSION
SODIUM CHLORIDES
MASS TRANSFER
MEDIUM TEMPERATURE
ONSAGER RELATIONS
REACTION KINETICS
SEA BED
SEAWATER
SEDIMENTS
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
KINETICS
MAGNESIUM COMPOUNDS
OXYGEN COMPOUNDS
SODIUM COMPOUNDS
WATER
152001* - Geothermal Data & Theory- Properties of Aqueous Solutions