arsenic thermodynamic data
TRANSCRIPT
Appendix C
Arsenic Thermodynamic Data
C.1 Introduction
Italicized terms in the text of this appendix or words derived from the italicized terms are defined in theglossary of Appendix B.
Table C.1 lists published thermodynamic data for arsenic, including: the more common elementalforms, selected compounds, and some aqueous and gaseous species. The table contains Gibbs free energy(�Gf ), enthalpy (�Hf ), entropy (S), and heat capacity (Cp) values at 1 bar pressure and mostly at298.15 K (25 ◦C). For thermodynamic data of chemical species not containing arsenic, extensive tablesoccur in geochemistry textbooks and other references, including: (Barin, 1995; Robie, Hemingway andFisher, 1979; Wagman et al., 1982; Drever, 1997; Eby, 2004; Faure, 1998; Lide, 2007; Krauskopf andBird, 1995). Thermodynamic data are important in examining the behavior of arsenic in mineral–waterinteractions, studying water quality issues, investigating the formation of ore deposits, developing andinterpreting Eh-pH diagrams, and designing environmental remediation projects (Nordstrom and Archer,2003, 1–2).
Not all published and widely accepted thermodynamic values are reliable. Nordstrom and Archer (2003)provide a detailed review of the controversies, uncertainties, and problems related to thermodynamic datafor arsenic and its compounds and aqueous species. Many of the data are contradictory and the methodsthat produce the data are sometimes questionable or have not been thoroughly documented. Too often,data in the literature have been passed from reference to reference without critical evaluations. Someof the data have high measurement errors, were produced under undefined or poorly defined laboratoryconditions, and involved unrepresentative sampling (Matschullat 2000, 298; Nordstrom and Archer, 2003).Furthermore, other questionable data originate from obscure documents or are written in languages thatmany individuals cannot read and properly interpret. Therefore, thermodynamic results must be acceptedwith a certain amount of caution. The table in this appendix includes thermodynamic data from varioussources, which provide users with some idea of their variability. Although sometimes unavoidable, users
Arse nic Edite d by K e vin R . He nke© 2009 John Wiley & Sons, Ltd. ISBN: 978-0-470-02758-5
476 Arsenic
are cautioned to avoid mixing data from different literature sources when performing calculations for areaction. Using data from multiple sources may introduce serious errors (Wagman et al., 1982; Eby, 2004,474).
C.2 Modeling applications with thermodynamic data
Once high-quality laboratory data are available, they may be used in geochemical computer models, suchas MINTEQA2 (Allison, Brown and Novo-Gradac, 1991) and PHREEQC (Parkhurst and Appelo, 1999).Langmuir (1997, 558–561) provides a brief review of the different types of geochemical models and theiradvantages and limitations. Geochemical models allow users to avoid tedious calculations. When properlyutilized, they may: (1) derive adsorption models, (2) identify probable aqueous species and estimate theiractivities, (3) model the effects of pH, reduction/oxidation (redox conditions), temperature, ionic strength,and other factors on arsenic chemistry, and/or (4) identify possible precipitates. However, as discussed inChapter 2, geochemical models are often incapable of accurately representing and predicting the complexbehavior of arsenic in natural environments. Specifically, the models typically fail to predict the presenceof metastable species, sluggish chemical reactions, and the effects of biological organisms.
C.3 Thermodynamic data
Arsenic Thermodynamic Data 477Ta
ble
C.1
Ther
mod
ynam
icda
tafo
rars
enic
,its
com
poun
ds,a
ndits
aque
ous
and
gase
ous
spec
ies
at1
barp
ress
ure.
Not
eth
atth
eun
itsof
Gi
and
Hi
are
1000
times
larg
erth
anS i
and
Cp i
.1kc
al=
4.18
4kJ
.◦C
=K
−273
.15.
(See
App
endi
xA
for
othe
run
itco
nver
sion
s).P
hase
sin
clud
e:am
orph
ous
(am
),aq
ueou
ssp
ecie
s(a
q),g
as,l
iqui
d(li
q),a
ndcr
ysta
lline
solid
s(x
ls).
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tCap
acity
(Cp i
)(J
mol
−1·K
−1)
Ref
eren
ce
Elem
enta
lA
s(0)
(ele
men
tala
rsen
ic,
rhom
bohe
dral
or‘g
ray’
)xl
s29
8.15
00
35.6
324
.43
Nor
dstr
oman
dA
rche
r(2
003)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
298.
150
035
.1—
Wag
man
etal
.(19
82)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
298.
150
035
.69
24.6
5R
obie
,Hem
ingw
ayan
dFi
sher
(197
9)A
s(0)
(ele
men
tala
rsen
ic,
rhom
bohe
dral
or‘g
ray’
)xl
s29
8.15
00
35.6
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)A
s(0)
(ele
men
tala
rsen
ic,
rhom
bohe
dral
or‘g
ray’
)xl
s29
8.15
00
35.7
0624
.652
Bar
in(1
995)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
400
00
43.0
425
.38
Rob
ie,H
emin
gway
and
Fish
er(1
979)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
400
00
43.0
6525
.388
Bar
in(1
995)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
500
00
48.7
725
.96
Rob
ie,H
emin
gway
,an
dFi
sher
(197
9)A
s(0)
(ele
men
tala
rsen
ic,
rhom
bohe
dral
or‘g
ray’
)xl
s50
00
048
.790
25.9
45B
arin
(199
5)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
600
00
53.5
526
.51
Rob
ie,H
emin
gway
and
Fish
er(1
979)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
600
00
53.5
6926
.501
Bar
in(1
995)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
700
00
57.6
827
.05
Rob
ie,H
emin
gway
and
Fish
er(1
979)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
700
00
57.6
9627
.054
Bar
in(1
995)
(con
tinue
dov
erle
af)
478 Arsenic
Tabl
eC
.1(c
ontin
ued)
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tCap
acity
(Cp i
)(J
mol
−1·K
−1)
Ref
eren
ce
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
800
00
61.3
327
.60
Rob
ie,H
emin
gway
and
Fish
er(1
979)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
800
00
61.3
4427
.580
Bar
in(1
995)
As(
0)(e
lem
enta
lars
enic
,rh
ombo
hedr
alor
‘gra
y’)
xls
875
00
63.8
228
.03
Rob
ie,H
emin
gway
and
Fish
er(1
979)
As(
0)(e
lem
enta
lars
enic
,am
orph
ous
or‘b
lack
’)am
298.
15—
4.2
——
Wag
man
etal
.(19
82)
As(
0)(e
lem
enta
lars
enic
,am
orph
ous
or‘b
lack
’)am
298.
15—
13.6
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
As+
gas
298.
15—
1255
.6—
—W
agm
anet
al.(
1982
)A
s2+ga
s29
8.15
—30
59.8
——
Wag
man
etal
.(19
82)
As3+
gas
298.
15—
5801
.1—
—W
agm
anet
al.(
1982
)A
s4+ga
s29
8.15
—10
644
——
Wag
man
etal
.(19
82)
As5+
gas
298.
15—
1669
4—
—W
agm
anet
al.(
1982
)A
s6+ga
s29
8.15
—29
045
——
Wag
man
etal
.(19
82)
As 2
gas
298.
1517
1.9
222.
223
9.4
35.0
03W
agm
anet
al.(
1982
)A
s 2ga
s29
8.15
143
194
242.
2—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
As 4
gas
298.
1592
.414
3.9
314
—W
agm
anet
al.(
1982
)A
s 4ga
s29
8.15
87.9
144
330
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)A
s 4ga
s29
8.15
98.2
6115
3.30
327.
4377
.208
Bar
in(1
995)
Gas
esan
daq
ueou
ssp
ecie
sof
arse
nic
com
poun
ds
Arsenic Thermodynamic Data 479
Ag 3
AsO
4xl
s29
8.15
−545
.39
−634
.29
275.
8317
3.86
Bar
in(1
995)
AlA
sxl
s29
8.15
—−1
16.3
——
Wag
man
etal
.(19
82)
AlA
sxl
s29
8.15
−115
.20
−116
.32
60.2
545
.80
Bar
in(1
995)
AlA
sO4
xls
298.
15−1
333.
1−1
431.
114
5.60
118.
34B
arin
(199
5)A
lAsO
4xl
s29
8.15
−128
0.8
——
—R
yuet
al.(
2002
)A
lAsO
4·2H
2O
(man
sfiel
dite
)xl
s29
8.15
−170
9—
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
AsB
r 3ga
s29
8.15
−161
.67
−132
.136
3.8
—Pa
nkra
tov
and
Uch
aeva
(200
0)A
sBr 3
gas
298.
15−1
59−1
3036
3.87
79.1
6W
agm
anet
al.(
1982
)A
sBr 3
gas
298.
15−1
59.8
0−1
30.0
036
3.99
78.9
92B
arin
(199
5)A
sCl 3
gas
298.
15−2
58.0
5−2
70.3
328.
8—
Pank
rato
van
dU
chae
va(2
000)
AsC
l 3ga
s29
8.15
−248
.9−2
61.5
327.
1775
.73
Wag
man
etal
.(19
82)
AsC
l 3ga
s29
8.15
−248
.66
−261
.50
327.
3075
.395
Bar
in(1
995)
AsC
l 3liq
298.
15−2
59.4
−305
.021
6.3
—W
agm
anet
al.(
1982
)A
sCl 3
liq29
8.15
−259
.08
−305
.01
216.
3113
3.47
Bar
in(1
995)
AsF
3ga
s29
8.15
−905
.67
−785
.828
9.0
—Pa
nkra
tov
and
Uch
aeva
(200
0)A
sF3
gas
298.
15−7
70.7
6−7
85.7
629
8.10
65.6
1W
agm
anet
al.(
1982
)A
sF3
gas
298.
15−7
70.6
5−7
85.7
628
9.22
64.6
84B
arin
(199
5)A
sF3
liq29
8.15
−774
.16
−821
.318
1.21
126.
57W
agm
anet
al.(
1982
)A
sF3
liq29
8.15
−774
.01
−821
.32
181.
2112
6.55
Bar
in(1
995)
AsF
5ga
s29
8.15
−117
2.5
−123
6.7
——
Pank
rato
van
dU
chae
va(2
000)
(con
tinue
dov
erle
af)
480 Arsenic
Tabl
eC
.1(c
ontin
ued)
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tCap
acity
(Cp i
)(J
mol
−1·K
−1)
Ref
eren
ce
AsF
5ga
s29
8.15
−116
9.0
−123
4.2
—87
.84
O’H
are
(199
3)A
sF5
gas
298.
15−1
169.
6−1
236.
831
7.26
97.5
41B
arin
(199
5)A
sH3
(ars
ine)
gas
298.
1568
.91
66.4
022
3.0
—Pa
nkra
tov
and
Uch
aeva
(200
0)A
sH3
(ars
ine)
gas
298.
1568
.93
66.4
422
2.78
38.0
7W
agm
anet
al.(
1982
)A
sH3
(ars
ine)
gas
298.
1568
.83
66.4
223
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)A
sH3
(ars
ine)
gas
298.
1569
.109
66.4
4222
2.78
38.0
72B
arin
(199
5)A
sI3
xls
298.
15−5
9.4
−58.
221
3.05
105.
77W
agm
anet
al.(
1982
)A
sI3
xls
298.
15−5
9.09
1−5
8.15
821
3.05
105.
77B
arin
(199
5)A
sI3
gas
298.
15—
—38
8.34
80.6
3W
agm
anet
al.(
1982
)A
sI3
gas
298.
15−1
5.32
138
.911
391.
8280
.960
Bar
in(1
995)
AsN
gas
298.
1516
7.97
196.
2722
5.6
30.4
2W
agm
anet
al.(
1982
)A
sOga
s29
8.15
−84.
715
−57.
287
230.
2732
.342
Bar
in(1
995)
As 2
O3
(ars
enol
ite,c
ubic
)xl
s29
8.15
−576
.34
−657
.27
107.
3896
.88
Nor
dstr
oman
dA
rche
r(2
003)
As 2
O3
(ars
enol
ite,c
ubic
)xl
s29
8.15
−576
−657
107.
4—
Rob
ie,H
emin
gway
and
Fish
er(1
979)
As 2
O3
(ars
enol
ite,c
ubic
)xl
s29
8.15
−588
.3−6
66.1
117
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)A
s 2O
3(a
rsen
olite
,cub
ic)
xls
298.
15−5
76.4
1—
——
Dav
iset
al.(
1996
)A
s 2O
3(a
rsen
olite
,cub
ic)
xls
298.
15−5
75.9
6−6
56.9
710
7.41
96.8
78B
arin
(199
5)A
s 2O
3(c
laud
etite
,m
onoc
linic
)xl
s29
8.15
−576
.53
−655
.67
113.
3796
.98
Nor
dstr
oman
dA
rche
r(2
003)
As 2
O3
(cla
udet
ite,
mon
oclin
ic)
xls
298.
15−5
76−6
5511
3.3
—R
obie
,Hem
ingw
ayan
dFi
sher
(197
9)A
s 2O
3(c
laud
etite
,m
onoc
linic
)xl
s29
8.15
−589
.1−6
64.0
127
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)
Arsenic Thermodynamic Data 481
As 2
O3
(cla
udet
ite,
mon
oclin
ic)
xls
298.
15−5
76.6
4−6
54.8
011
7.00
96.9
79B
arin
(199
5)
As 2
O3·SO
3xl
s29
8.15
—−1
194.
32—
—W
agm
anet
al.(
1982
)A
s 2O
5xl
s29
8.15
−774
.96
−917
.59
105.
4411
5.9
Nor
dstr
oman
dA
rche
r(2
003)
As 2
O5
xls
298.
15−7
82.0
−924
.710
5—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
As 2
O5
xls
298.
15−7
82.7
8—
——
Dav
iset
al.(
1996
)A
s 2O
5xl
s29
8.15
−782
.3−9
24.8
710
5.4
116.
52W
agm
anet
al.(
1982
)A
s 2O
5xl
s29
8.15
−782
.09
−924
.87
105.
4011
6.54
Bar
in(1
995)
As 2
O5
xls
400
−733
.31
−924
.59
142.
6213
6.54
Bar
in(1
995)
As 2
O5
xls
500
−685
.66
−922
.93
174.
7715
1.78
Bar
in(1
995)
As 2
O5·4H
2O
xls
298.
15—
−210
4.6
——
Wag
man
etal
.(19
82)
As 2
O5·4H
2O
xls
298.
15−1
720
——
—Fa
ure
(199
8)(A
s 2O
5) 3
·5H2O
xls
298.
15—
−424
8.4
——
Wag
man
etal
.(19
82)
As 4
O6
gas
298.
15−1
092.
2−1
196.
240
9.35
173.
60B
arin
(199
5)A
sS(α
,rea
lgar
)xl
s29
8.15
−31.
3−3
1.8
62.9
47N
ords
trom
and
Arc
her
(200
3)A
sS(α
,rea
lgar
)xl
s29
8.15
−35
−36
63.5
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)A
sS(β
)xl
s29
8.15
−30.
9−3
1.0
63.5
47N
ords
trom
and
Arc
her
(200
3)A
sS(O
H)(S
H)−
aq29
8.15
−245
.11
——
—H
elz
etal
.(19
95)
As 2
S 3am
298.
15−7
6.8
−66.
920
0—
Nor
dstr
oman
dA
rche
r(2
003)
As 2
S 3(o
rpim
ent)
xls
298.
15−8
4.9
−85.
816
3.8
163
Nor
dstr
oman
dA
rche
r(2
003)
As 2
S 3(o
rpim
ent)
xls
298.
15−9
5.4
−96.
216
4—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
As 3
S 4(S
H)− 2
aq29
8.15
−127
.19
——
—H
elz
etal
.(19
95)
(con
tinue
dov
erle
af)
482 Arsenic
Tabl
eC
.1(c
ontin
ued)
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tCap
acity
(Cp i
)(J
mol
−1·K
−1)
Ref
eren
ce
As 2
Se3
xls
298.
15−8
8.4
−86.
17.
8—
O’H
are
etal
.(19
90)
As 2
Se3
xls
298.
15—
−81.
1—
—O
’Har
e(1
993)
As 2
Se3
xls
298.
15−1
01.4
3−1
02.5
119
4.56
121.
39B
arin
(199
5)A
s 2Se
3am
298.
15—
−53.
1—
—O
’Har
e(1
993)
As 2
Te3
xls
298.
15−3
9.58
0−3
7.65
622
6.35
127.
49B
arin
(199
5)B
a 3(A
sO4) 2
xls
298.
15−3
113.
40—
——
Zhu
etal
.(20
05)
Ba 3
(AsO
4) 2
xls
298.
15−3
192.
2−3
421.
730
9.62
257.
21B
arin
(199
5)B
aHA
sO4·H
2O
xls
298.
15−1
544.
47—
——
Zhu
etal
.(20
05)
Be 3
(AsO
4) 2
xls
298.
15−2
525.
5−2
738.
120
7.28
232.
52B
arin
(199
5)B
iAsO
4xl
s29
8.15
−619
——
—W
agm
anet
al.(
1982
)B
iAsO
4xl
s29
8.15
−695
.43
−795
.21
168.
0712
1.12
Bar
in(1
995)
BiA
sO4
(roo
seve
ltite
)xl
s29
8.15
−613
.58
——
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)(C
H3) 3
As
gas
298.
15—
12—
—Pa
nkra
tov
and
Uch
aeva
(200
0)C
a(H
2A
sO4) 2
xls
298.
15−2
054
——
—R
yuet
al.(
2002
)C
a 2A
sO4O
Hxl
s29
8.15
−198
8—
——
Ryu
etal
.(20
02)
Ca 3
(AsO
4) 2
xls
298.
15−3
061
——
—R
yuet
al.(
2002
)C
a 3(A
sO4) 2
xls
298.
15−3
063.
1−3
298.
722
6.00
249.
79B
arin
(199
5)C
a 3(A
sO4) 2
xls
298.
15−3
063.
0−3
298.
722
6—
Wag
man
etal
.(19
82)
Ca 3
(AsO
4) 2
·2.25
H2O
xls
298.
15−3
611.
50—
——
Zhu
etal
.(20
06)
Ca 3
(AsO
4) 2
·3H2O
xls
298.
15−3
787.
87—
——
Zhu
etal
.(20
06)
Ca 3
(AsO
4) 2
·3.67
H2O
xls
296
−394
5—
——
Bot
hean
dB
row
n(1
999)
Ca 3
(AsO
4) 2
·4H2O
xls
298.
15−4
019
——
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)C
a 3(A
sO4) 2
·4.25
H2O
xls
296
−408
5—
——
Bot
hean
dB
row
n(1
999)
Arsenic Thermodynamic Data 483
Ca 3
(AsO
4) 2
·6H2O
xls
298.
15−2
732
——
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)C
a 3(A
sO4) 2
·8H2O
xls
298.
15−3
530
——
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)C
a 4(O
H) 2
(AsO
4) 2
·4H2O
xls
296
−494
1—
——
Bot
hean
dB
row
n(1
999)
Ca 4
(OH
) 2(A
sO4) 2
·4H2O
xls
298.
15−4
928.
86—
——
Zhu
etal
.(20
06)
Ca 5
(AsO
4) 3
OH
xls
296
−508
7—
——
Bot
hean
dB
row
n(1
999)
Ca 5
(AsO
4) 3
OH
xls
298.
15−5
096.
47—
——
Zhu
etal
.(20
06)
Ca 5
H2(A
sO4) 4
xls
298.
15−5
636.
7—
——
Ryu
etal
.(20
02)
Ca 5
H2(A
sO4) 4
·9H2O
(ferr
aris
ite)
xls
296
−780
8—
——
Bot
hean
dB
row
n(1
999)
Ca 5
H2(A
sO4) 4
·9H2O
(gue
rini
te)
xls
296
−780
3—
——
Bot
hean
dB
row
n(1
999)
CaH
(AsO
4)·H
2O
xls
296
−153
3—
——
Bot
hean
dB
row
n(1
999)
CaH
AsO
0 4aq
298.
15—
−144
6.0
——
Wag
man
etal
.(19
82)
Cd 3
(AsO
4) 2
xls
298.
15−1
716.
1—
——
Wag
man
etal
.(19
82)
Cd 3
(AsO
4) 2
xls
298.
15−1
712.
0−1
934.
330
1.71
258.
82B
arin
(199
5)C
d 3A
s 2xl
s29
8.15
—−4
1.8
——
Wag
man
etal
.(19
82)
Cd 3
As 2
xls
298.
15−3
5.88
5−4
1.84
020
6.83
125.
30B
arin
(199
5)C
dAs 2
xls
298.
15—
−17.
6—
—W
agm
anet
al.(
1982
)C
oAs
xls
298.
15—
−40.
6—
—W
agm
anet
al.(
1982
)C
oAs
(mod
deri
te)
xls
298.
15−4
9−5
159
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)C
oAs 2
xls
298.
15—
−61.
5—
—W
agm
anet
al.(
1982
)C
oAs 2
(saf
flori
te)
xls
298.
15−9
7−8
310
0—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
(con
tinue
dov
erle
af)
484 Arsenic
Tabl
eC
.1(c
ontin
ued)
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tC
apac
ity(C
p i)(
Jm
ol−1
·K−1
)
Ref
eren
ce
Co 2
As
xls
298.
15—
−39.
7—
—W
agm
anet
al.(
1982
)C
o 2A
s 3xl
s29
8.15
—−9
7.5
——
Wag
man
etal
.(19
82)
Co 3
As 2
xls
298.
15—
−81.
2—
—W
agm
anet
al.(
1982
)C
o 5A
s 2xl
s29
8.15
—−7
9.5
——
Wag
man
etal
.(19
82)
Co 3
(AsO
4) 2
xls
298.
15−1
620.
8—
——
Wag
man
etal
.(19
82)
Co 3
(AsO
4) 2
xls
298.
15−1
671.
9−1
864.
333
7.02
264.
31B
arin
(199
5)C
rAsO
4xl
s29
8.15
−968
.36
−106
2.1
155.
3511
9.10
Bar
in(1
995)
Cr 3
(AsO
4) 2
xls
298.
15−2
027.
0−2
218.
232
1.42
261.
83B
arin
(199
5)C
s 3A
sO4
xls
298.
15−1
543.
9−1
668.
528
3.59
176.
22B
arin
(199
5)C
u 3A
sxl
s29
8.15
—−1
1.7
——
Wag
man
etal
.(19
82)
Cu 3
As
xls
298.
15−1
2.32
2−1
1.71
513
7.24
93.0
80B
arin
(199
5)C
u 3(A
sO4)
xls
298.
15−6
24.0
4−7
10.3
625
5.98
176.
36B
arin
(199
5)—
xls
298.
15−1
300.
7—
——
Wag
man
etal
.(19
82)
Cu 3
(AsO
4) 2
xls
298.
15−1
301.
32—
——
Dav
iset
al.(
1996
)C
u 3(A
sO4) 2
xls
298.
15−1
316.
0−1
522.
629
8.61
258.
21B
arin
(199
5)C
u 3(A
sO4) 2
·6H2O
xls
298.
15−2
733.
04—
——
Dav
iset
al.(
1996
)C
u 3A
sS4
(ena
rgite
)xl
s29
8.15
−206
.74
−179
.035
6.4
—C
astr
oan
dB
altie
rra
(200
5)an
dK
anta
r(2
002)
Cu 3
AsS
4(e
narg
ite)
xls
298.
15—
—25
7.6
190.
4Se
alet
al.(
1996
)C
u 3A
sS4
(ena
rgite
)xl
s29
8.15
−437
.26
——
—D
avis
etal
.(19
96)
Fe3(A
sO4) 2
xls
298.
15−1
753.
93—
——
Dav
iset
al.(
1996
)Fe
3(A
sO4) 2
·8H2O
(sym
ples
ite)
xls
298.
15−3
687.
26—
——
Dav
iset
al.(
1996
)
FeA
s(w
este
rvel
dite
)xl
s29
8.15
−43.
36−4
3.51
62.5
50.3
6Pe
rfet
tiet
al.(
2008
)Fe
As 2
(loel
lingi
te)
xls
298.
15−5
2.09
−43.
512
7N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)
Arsenic Thermodynamic Data 485
FeA
sO4
xls
298.
15−7
72.3
9−8
65.3
416
1.54
117.
05B
arin
(199
5)Fe
AsO
4xl
s29
8.15
−772
.62
——
—R
yuet
al.(
2002
)Fe
AsO
4·2H
2O
(sco
rodi
te)
xls
298.
15−1
280.
1—
——
Ryu
etal
.(20
02)
FeA
sO4·2H
2O
(sco
rodi
te)
xls
296
−127
9.2
——
—K
raus
ean
dEt
tel
(198
8)Fe
AsO
4·2H
2O
(sco
rodi
te)
xls
298.
15−1
267.
69—
——
Dav
iset
al.(
1996
)Fe
3(A
sO4) 2
xls
298.
15−1
766.
0−1
955.
033
9.91
264.
64B
arin
(199
5)Fe
AsS
(ars
enop
yrite
)xl
s29
8−1
36.4
5−1
44.3
668
.568
.44
Perf
etti
etal
.(20
08)
FeA
sS(a
rsen
opyr
ite)
xls
298
−141
.6—
——
Pokr
ovsk
i,K
ara
and
Rou
x(2
002)
FeA
sS(a
rsen
opyr
ite)
xls
298.
15−1
27.2
5—
——
Dav
iset
al.(
1996
)Fe
AsS
2(lo
ellin
gite
)xl
s29
8.15
−80.
23−8
5.77
80.1
70.8
3Pe
rfet
tiet
al.(
2008
)Fe
AsS
2(lo
ellin
gite
)xl
s29
8.15
−52.
116
——
—D
avis
etal
.(19
96)
GaA
s(g
alliu
mar
seni
de)
xls
298.
15−6
7.8
−71
64.1
846
.23
Wag
man
etal
.(19
82)
GaA
s(g
alliu
mar
seni
de)
xls
298.
15−7
0.37
4−7
4.05
764
.183
46.8
58B
arin
(199
5)G
aAs
(gal
lium
arse
nide
)xl
s29
8.15
−67.
8−7
164
.2—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
GaA
sO4
xls
298.
15−9
01.8
5−1
002.
215
0.12
118.
26B
arin
(199
5)H
3A
sO0 3
aq29
8.15
−639
.8−7
37.3
212.
485
.0Pe
rfet
tiet
al.(
2008
)H
3A
sO0 3
aq29
8.15
−640
.03
−742
.36
195.
8—
Nor
dstr
oman
dA
rche
r(2
003)
H3A
sO0 3
aq29
8.15
−639
.78
−740
.82
200
197
Pokr
ovsk
iet
al.
(199
6)H
2A
sO− 3
aq29
8.15
−587
.13
−714
.79
110.
5—
Wag
man
etal
.(19
82)
H2A
sO− 3
aq29
8.15
−587
.66
−714
.74
112.
79—
Nor
dstr
oman
dA
rche
r(2
003)
HA
sO2− 3
aq29
8.15
−524
−689
−15
—D
ove
and
Rim
stid
t(1
985)
(con
tinue
dov
erle
af)
486 Arsenic
Tabl
eC
.1(c
ontin
ued)
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tCap
acity
(Cp i
)(J
mol
−1·K
−1)
Ref
eren
ce
HA
sO2− 3
aq29
8.15
−524
.3—
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
AsO
3− 3aq
298.
15−4
48−6
64−1
87—
Dov
ean
dR
imst
idt
(198
5)A
sO3− 3
aq29
8.15
−447
.7—
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
H3A
sO0 4
aq29
8.15
−766
.3−8
98.6
198.
310
5.0
Perf
etti
etal
.(20
08)
H3A
sO0 4
aq29
8.15
−766
.75
−903
.45
183.
07—
Nor
dstr
oman
dA
rche
r(2
003)
H2A
sO− 4
aq29
8.15
−753
.17
−909
.56
117
—W
agm
anet
al.(
1982
)H
2A
sO− 4
aq29
8.15
−753
.65
−911
.42
112.
38—
Nor
dstr
oman
dA
rche
r(2
003)
HA
sO2− 4
aq29
8.15
−713
.73
−908
.41
−11.
42—
Nor
dstr
oman
dA
rche
r(2
003)
HA
sO2− 4
aq29
8.15
−714
.60
−906
.34
——
Wag
man
etal
.(19
82)
AsO
3− 4aq
298.
15−6
46.3
6−8
90.2
1−1
76.3
1—
Nor
dstr
oman
dA
rche
r(2
003)
HA
sO3F−
aq29
8.15
−106
0.96
——
—W
agm
anet
al.(
1982
)A
sO3F2−
aq29
8.15
−102
7.45
——
—W
agm
anet
al.(
1982
)H
g 3(A
sO4) 2
xls
298.
15−1
033.
6−1
271.
032
3.47
261.
72B
arin
(199
5)In
As
(indi
umar
seni
de)
xls
298.
15−5
3.6
−58.
675
.747
.78
Wag
man
etal
.(19
82)
InA
s(in
dium
arse
nide
)xl
s29
8.15
−53.
286
−58.
601
75.7
0147
.780
Bar
in(1
995)
InA
s(in
dium
arse
nide
)xl
s29
8.15
−52.
7−5
7.7
75.7
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)In
AsO
4xl
s29
8.15
−874
.26
−978
.30
154.
8511
9.32
Bar
in(1
995)
KA
sxl
s29
8.15
—−1
02.9
——
Wag
man
etal
.(19
82)
Arsenic Thermodynamic Data 487
KA
s 2xl
s29
8.15
—−1
27.2
——
Wag
man
etal
.(19
82)
K3A
sxl
s29
8.15
—−1
86.2
——
Wag
man
etal
.(19
82)
K5A
s 4xl
s29
8.15
—−4
52.7
——
Wag
man
etal
.(19
82)
KH
2A
sO4
xls
298.
15−1
035.
9−1
180.
715
5.02
126.
73W
agm
anet
al.(
1982
)K
H2A
sO4
xls
298.
15−1
041.
6−1
186.
215
5—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
K3(A
sO4)
xls
298.
15−1
548.
8−1
668.
723
7.82
172.
29B
arin
(199
5)K
UO
2A
sO4
xls
298.
15−2
021.
1—
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
LaA
sO4
xls
298.
15−1
455.
7−1
556.
916
3.47
117.
89B
arin
(199
5)Li
3(A
sO4)
xls
298.
15−1
595.
0−1
702.
417
3.13
161.
84B
arin
(199
5)M
gAs 4
xls
298.
15—
−126
——
Wag
man
etal
.(19
82)
Mg 3
As 2
xls
298.
15—
−371
.5—
—W
agm
anet
al.(
1982
)M
g 3(A
sO4) 2
xls
298.
15—
−309
2.8
——
Wag
man
etal
.(19
82)
Mg 3
(AsO
4) 2
xls
298.
15−2
775
——
—R
yuet
al.(
2002
)
(con
tinue
dov
erle
af)
488 Arsenic
Tabl
eC
.1(c
ontin
ued)
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tCap
acity
(Cp i
)(J
mol
−1·K
−1)
Ref
eren
ce
Mg 3
(AsO
4) 2
xls
298.
15−2
831.
7−3
059.
822
5.10
236.
31B
arin
(199
5)M
g 3(A
sO4) 2
·10H
2O
xls
298.
15−5
147.
2—
——
Ryu
etal
.(20
02)
MgH
AsO
4xl
s29
8.15
−118
7—
——
Ryu
etal
.(20
02)
MgH
AsO
4·7H
2O
(roe
ssle
rite
)xl
s29
8.15
−284
8—
——
Ryu
etal
.(20
02)
MgN
H4A
sO4·6H
2O
xls
298.
15—
−331
6.7
——
Wag
man
etal
.(19
82)
MnA
s(α
)xl
s29
8.15
−61.
636
−51.
861
107.
0071
.116
Bar
in(1
995)
MnA
s(β
)xl
s29
8.15
−59.
865
−53.
297
91.4
4270
.340
Bar
in(1
995)
MnA
s(γ
)xl
s29
8.15
−59.
691
−56.
902
77.0
6970
.164
Bar
in(1
995)
MnA
sxl
s29
8.15
—−5
9—
—W
agm
anet
al.(
1982
)M
nAs
(kan
eite
)xl
s29
8.15
−55.
2−5
7.3
60—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
Mn 3
(AsO
4) 2
xls
298.
15−2
167.
4—
——
Ryu
etal
.(20
02)
Mn 3
(AsO
4) 2
xls
298.
15—
−214
5.6
——
Wag
man
etal
.(19
82)
Mn 3
(AsO
4) 2
xls
298.
15−2
167.
0−2
366.
331
9.62
261.
79B
arin
(199
5)M
n 3(A
sO4) 2
·8H2O
xls
298.
15−4
055
——
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)M
nHA
sO4
xls
298.
15—
−110
2.5
——
Wag
man
etal
.(19
82)
MoA
sO4
xls
298.
15−8
17.7
9−9
10.6
916
3.01
120.
06B
arin
(199
5)N
aAs
xls
298.
15−8
9.1
−96.
262
.8—
Wag
man
etal
.(19
82)
NaA
s 2xl
s29
8.15
−100
.4−1
06.7
100
—W
agm
anet
al.(
1982
)N
a 3A
sxl
s29
8.15
−187
.4−2
0513
0—
Wag
man
etal
.(19
82)
Na 3
As
xls
298.
15−1
87.1
0−2
05.0
213
0.00
97.7
69B
arin
(199
5)
Arsenic Thermodynamic Data 489
NaA
sO2
xls
298.
15—
−660
.53
——
Wag
man
etal
.(19
82)
NaU
O2A
sO4·4H
2O
xls
298.
15−2
944.
6—
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
Na 3
AsO
4xl
s29
8.15
—−1
540
——
Wag
man
etal
.(19
82)
Na 3
AsO
4xl
s29
8.15
−142
6.0
−154
0.0
217.
9417
0.13
Bar
in(1
995)
Na 3
AsO
4·12
H2O
xls
298.
15—
−509
2—
—W
agm
anet
al.(
1982
)N
iAs
(nic
kelin
e,ni
ccol
ite)
xls
298.
15—
—61
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)N
iAs
xls
298.
15−6
7.26
8−7
3.29
145
.380
56.0
01B
arin
(199
5)N
i 3(A
sO4) 2
xls
298.
15−1
579.
3—
——
Wag
man
etal
.(19
82)
Ni 3
(AsO
4) 2
xls
298.
15−1
659.
4−1
849.
234
4.80
265.
41B
arin
(199
5)N
i 3(A
sO4) 2
·8H2O
(Ann
aber
gite
)xl
s29
8.15
−348
2—
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
Ni 5
As 2
xls
298.
15−2
42.1
1−2
51.1
019
0.63
215.
98B
arin
(199
5)N
i 11A
s 8xl
s29
8.15
−762
.63
−774
.04
468.
8855
2.00
Bar
in(1
995)
NH
4H
2A
sO4
xls
298.
15−8
32.9
−105
9.8
172.
0515
1.17
Wag
man
etal
.(19
82)
(con
tinue
dov
erle
af)
490 Arsenic
Tabl
eC
.1(c
ontin
ued)
Che
mic
alsp
ecie
sPh
ase
Tem
pera
ture
(K)
Gib
bsfr
eeen
ergy
(Gi)
(kJm
ol−1
)
Enth
alpy
(Hi)
(kJm
ol−1
)En
trop
y(S
i)(J
mol
−1·K
−1)
Hea
tCap
acity
(Cp i
)(J
mol
−1·K
−1)
Ref
eren
ce
NH
4H
2A
sO4
xls
298.
15−8
37.3
4−1
064.
117
2—
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
(NH
4) 2
HA
sO4
xls
298.
15—
−118
1.6
——
Wag
man
etal
.(19
82)
(NH
4) 3
AsO
4xl
s29
8.15
—−1
286.
2—
—W
agm
anet
al.(
1982
)(N
H4) 3
AsO
4·3H
2O
xls
298.
15—
−216
6.9
——
Wag
man
etal
.(19
82)
Pb3(A
sO4) 2
xls
298.
15−1
553.
1−1
780.
232
4.60
258.
00B
arin
(199
5)Pb
3(A
sO4) 2
xls
298.
15−1
580.
01—
——
Dav
iset
al.(
1996
)Pb
3(A
sO4) 2
xls
298.
15−1
579.
3—
——
Nau
mov
,Ryz
henk
oan
dK
hoda
kovs
ky(1
974)
Pb5(A
sO4) 3
Cl(
mim
etite
)xl
s29
8.15
−261
6.25
——
—D
avis
etal
.(19
96)
Pb5(A
sO4) 3
OH
xls
298.
15−2
659
——
—Le
ean
dN
riag
u(2
007)
PbH
AsO
4xl
s29
8.15
−805
.66
——
—Le
ean
dN
riag
u(2
007)
Rb 3
(AsO
4)
xls
298.
15−1
547.
0−1
669.
026
7.06
175.
28B
arin
(199
5)R
e 3A
s 7xl
s29
8.15
−88.
624
−95.
395
336.
8124
8.64
Bar
in(1
995)
ReA
sO4
xls
298.
15−6
78.3
9−7
71.5
717
0.00
121.
37B
arin
(199
5)Sn
3(A
sO4) 2
xls
298.
15−1
564.
6−1
785.
830
3.93
259.
1B
arin
(199
5)Sr
3(A
sO4) 2
xls
298.
15−3
094.
4−3
317.
131
2.1
257.
6B
arin
(199
5)Ti
3(A
sO4) 2
xls
298.
15−2
547.
3−2
617.
333
9.4
264.
5B
arin
(199
5)
Arsenic Thermodynamic Data 491
TlA
sO4
xls
298.
15−8
85.8
1−9
48.5
629
9.74
145.
69B
arin
(199
5)Y
AsO
4xl
s29
8.15
−141
6.8
−151
5.1
160.
5412
0.75
Bar
in(1
995)
Zn 3
(AsO
4) 2
xls
298.
15−1
895.
91—
——
Dav
iset
al.(
1996
)Z
n 3(A
sO4) 2
xls
298.
15−1
895
——
—W
agm
anet
al.(
1982
)Z
n 3(A
sO4) 2
xls
298.
15−1
915.
6−2
134.
728
1.92
255.
28B
arin
(199
5)Z
n 3(A
sO4) 2
·2.5H
2O
(legr
andi
te)
xls
298.
15−2
611
——
—N
aum
ov,R
yzhe
nko
and
Kho
dako
vsky
(197
4)Z
nAs 2
xls
298.
15—
−41.
8—
—W
agm
anet
al.(
1982
)Z
n 3A
s 2xl
s29
8.15
−125
.46
−133
.89
168.
0412
5.23
Bar
in(1
995)
Zn 3
As 2
xls
298.
15—
−32.
2—
—W
agm
anet
al.(
1982
)
492 Arsenic
References
Allison, J.D., Brown, D.S. and Novo-Gradac, K.J. (1991) MINTEQA2/PRODEFA2: A Geochemical Assessment Modelfor Environmental Systems: Version 3.0 User’s Manual , U.S. Environmental Protection Agency, Washington, DC.
Barin, I. (1995) Thermochemical Data of Pure Substances: Parts 1 and II , 3rd edn. Weinheim, VCH Verlagsgesellschaft,1885 pp.
Bothe, J.V. Jr. and Brown, P.W. (1999) The stabilities of calcium arsenates at 23 ± 1 ◦C. Journal of HazardousMaterials , 69(2), 197–207.
Castro, S.H. and Baltierra, L. (2005) Study of the surface properties of enargite as a function of pH. InternationalJournal of Mineral Processing , 77(2), 104–15.
Davis, A., Ruby, M.V., Bloom, M. et al. (1996) Mineralogic constraints on the bioavailability of arsenic insmelter-impacted soils. Environmental Science and Technology , 30(2), 392–99.
Dove, P.M. and Rimstidt, J.D. (1985) The solubility and stability of scorodite, FeAsO4.2H2O. American Mineralogist ,70(7–8), 838–44.
Drever, J.I. (1997) The Geochemistry of Natural Waters: Surface and Groundwater Environments , Upper Saddle River,NJ, Prentice Hall, 436 pp.
Eby, G.N. (2004) Principles of Environmental Geochemistry , Brooks/Cole-Thomson Learning, Pacific Grove, CA,514 pp.
Faure, G. (1998) Principles and Applications of Geochemistry , 2nd edn. Prentice Hall, Upper Saddle River, NJ,600 pp.
Helz, G.R., Tossell, J.A., Charnock, J.M. et al. (1995) Oligomerization in As(III) sulfide solutions: theoretical con-straints and spectroscopic evidence. Geochimica et Cosmochimica Acta , 59(22), 4591–604.
Kantar, C. (2002) Solution and flotation chemistry of enargite. Colloids and Surfaces A: Physicochemical and Engi-neering Aspects , 210(1), 23–31.
Krause, E. and Ettel, V.A. (1988) Solubility and stability of scorodite, FeAsO4.2H2O: new data and further discussion.American Mineralogist , 73(7–8), 850–54.
Krauskopf, K.B. and Bird, D.K. (1995) Introduction to Geochemistry , 3rd edn. McGraw-Hill, Boston.Langmuir, D. (1997) Aqueous Environmental Geochemistry , Upper Saddle River, NJ, Prentice Hall, 600 pp.Lee, J.S. and Nriagu, J.O. (2007) Stability constants for metal arsenates. Environmental Chemistry , 4(2), 123–33.Lide, D.R. (ed) (2007) CRC Handbook of Chemistry and Physics , 88th edn. CRC Press, Boca Raton, FL.Matschullat, J. (2000) Arsenic in the geosphere –A review. Science of the Total Environment , 249(1–3), 297–312.Naumov, G.B., Ryzhenko, B.N. and Khodakovsky, I.L. (1974) Handbook of Thermodynamic Data, (English trans-
lation). PB 226 722, Report No. USGS-WRD-74-001, U.S. Geological Survey, Menlo Park California, NationalTechnical Information Service, Springfield, Virginia.
Nordstrom, D.K. and Archer, D.G. (2003) Arsenic thermodynamic data and environmental geochemistry, in Arsenicin Ground Water , (eds A.H. Welch and K.G. Stollenwerk), Kluwer Academic Publishers, Boston, pp. 1–25.
O’Hare, P.A.G. (1993) Calorimetric measurements of the specific energies of reaction of arsenic and of seleniumwith fluorine. Standard molar enthalpies of formation �fH
om at the temperature 2.98.15 K of AsF5, SeF6, As2Se3,
As4S4, and As2S3. Thermodynamic properties of AsF5 and SeF6 in the ideal-gas state. Critical assessment of �fHo
m
(AsF3, l)), and the dissociation enthalpies of As-F bonds. Journal of Chemical Thermodynamics , 25, 391–402.O’Hare, P.A.G., Lewis, B.M., Susman, S. and Volin, K.J. (1990) Standard molar enthalpies of formation and tran-
sition at the temperature 298.15 K and other thermodynamic properties of the crystalline and vitreous forms ofarsenic sesquiselenide (As2S3). Dissociation enthalpies of As-Se bonds. Journal of Chemical Thermodynamics , 22,1191–206.
Pankratov, A.N. and Uchaeva, I.M. (2000) A semiempirical quantum chemical testing of thermodynamic and molecularproperties of arsenic compounds. Journal of Molecular Structure (Theochem), 498, 247–54.
Parkhurst, D.L. and Appelo, C.A.J. (1999) User’s Guide to PHREEQC (Version 2): A Computer Program for Speci-ation, Batch-reaction, One-dimensional transport, and Inverse Geochemical Calculations. U.S. Geological SurveyWater-Resources Investigations Report 99-4259, 312 pp.
Arsenic Thermodynamic Data 493
Perfetti, E., Pokrovski, G.S., Ballerat-Busserolles, K. et al. (2008) Densities and heat capacities of aqueous arse-nious and arsenic acid solutions to 350 ◦C and 300 bar, and revised thermodynamic properties of As(OH)3
o(aq),AsO(OH)3
o(aq) and iron sulfarsenide minerals. Geochimica et Cosmochimica Acta , 72(3), 713–31.Pokrovski, G., Gout, R., Schott, J. et al. (1996) Thermodynamic properties and stoichiometry of As(III) hydroxide
complexes at hydrothermal conditions. Geochimica et Cosmochimica Acta , 60(5), 737–49.Pokrovski, G.S., Kara, S. and Roux, J. (2002) Stability and solubility of arsenopyrite, FeAsS, in crustal fluids. Geochim-
ica et Cosmochimica Acta, 66(13), 2361–78.Robie, R.A., Hemingway, B.S. and Fisher, J.R. (1979) Thermodynamic Properties of Minerals and Related Substances
at 298.15 K and 1 Bar (105 Pascals) Pressure and at Higher Temperatures , Reprinted with corrections. GeologicalSurvey Bulletin 1452, United States Printing Office, Washington, DC, 456 pp.
Ryu, J-H., Gao, S., Dahlgren, R.A. and Zierenberg, R.A. (2002) Arsenic distribution, speciation and solubility inshallow groundwater of Owens Dry Lake, California. Geochimica et Cosmochimica Acta , 66(17), 2981–94.
Seal, R.R. II, Robie, R.A., Hemingway, B.S. and Evans, H.T. Jr (1996) Heat capacity and entropy at the temperatures5 K to 720 K and thermal expansion from the temperatures 298 K to 573 K of synthetic enargite (Cu3AsS4).Journal of Chemical Thermodynamics , 28(4), 405–12.
Wagman, D.D., Evans, W.H., Parker, V.B. et al. (1982) The NBS tables of chemical thermodynamic properties:selected values for inorganic and C1 and C2 organic substances in SI units. Journal of Physical and ChemicalReference Data , 11(2), 1–392.
Zhu, Y., Zhang, X., Xie, Q. et al. (2005) Solubility and stability of barium arsenate and barium hydrogen arsenate at25◦C. Journal of Hazardous Materials , 120(1-3), 37–44.
Zhu, Y.N., Zhang, X.H., Xie, Q.L. et al. (2006) Solubility and stability of calcium arsenates at 25◦C. Water, Air, andSoil Pollution, 169(1–4), 221–38.