ARS PESTICIDE PROPERTIES DATABASE last updated Oct 1, 2001


name: ARSENIC ACID                              CASRN: 7778-39-4


SELECTED VALUES FOR MODELING PURPOSES (from Hornsby, et al., 1996)

WATER SOLUBILITY (mg/L): 17000
FIELD HALF-LIFE (days): 10000 E {1}
SOIL ORGANIC CARBON SORPTION (Koc, mL/g): 100000 E {2}
VAPOR PRESSURE (mm Hg): 0
pKa: 2.3; 7.1; 11.6 {3}


PUBLISHED AND MANUFACTURER VALUES AND SOURCES

molecular formula: H3AsO4.1/2H2O
molecular weight : 159.9
physical state   : S
(L=liquid; G=gas; S=solid)
reference: 9MERCK

_________________________________________________________________________
Key to sources: (M)Manufacturer, (R)eview, (H)andbook, (E)xperiment,
                (C)alculated, (U)nknown, (P)EPA data, (W)auchope

* denotes a selected value where multiple values of a property are listed.
_________________________________________________________________________

-value-            -medium-   -temp-  -pH-   -source-    -reference-


Boiling point(deg C):
       -

Melting point(deg C):
35     -                                        H       9MERCK

Decomposition point(deg C):
160    -

Heat of vaporization(deg C):

--RATE CONSTANTS--

Hydrolysis (per day):

Photolysis (per day):

Vapor pressure (mPa):
0.0*                                            H         9MERCK  


Water solubility (ppm):       -temp-        -source-     -reference-

Organic solubility (ppm):

Henrys law (Pa m3/mol):

Octanol/water partitioning (log Kow):

Acid dissociation (pKa):
2.3*                                              E   JAFCAU,24:717,1976
7.1*                                              E   JAFCAU,24:717,1976


Soil sorption:
soiltype        temp.   Kd      Koc      %om   pH         reference

Field Dissipation halflife(days):
value             test area        pH           source    reference

Halflife in soil:
Soiltype               aerobic      anaerobic   source    reference

Comments:
DECOMPOSITION VALUE AT 160 = LOSS OF WATER OF HYDRATION