updated: 31 march 2020 print version · (stumm & morgan, chapt.7) benjamin; chapter 8.7-8.15....
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Lecture #37Precipitation and Dissolution: Metal
Hydroxides/Oxides & Carbonates(Stumm & Morgan, Chapt.7)
Benjamin; Chapter 8.7-8.15
David Reckhow CEE 680 #37 1
Updated: 31 March 2020 Print version
Practice Session
Al(OH)3 pptHomework
Cr(OH)3 pptZn(OH)2 pptCd(OH)2 ppt
David Reckhow CEE 680 #37 2
Metal Precipitates; Kso values (1/2)
Table 11.1a in Benjamin (pg 581)
David Reckhow CEE 680 #37 3
Metal Precipitates; Kso values (2/2)
Table 11.1b in Benjamin (pg 582)
David Reckhow CEE 680 #37 4
Metal Hydrolysis Table 10.2 in
Benjamin Pg 858-859
David Reckhow CEE 680 #37 5
Cd(OH)2 example Cd species equations
From Benjamin, pg 584
David Reckhow CEE 680 #37 6
Cd(OH)2 solubility diagram Pg 586 in Benjamin
David Reckhow CEE 680 #37 7
Zinc with OH, CO3 and Cl Pg 636 in Benjamin
David Reckhow CEE 680 #37 8
Zn
sol
ubili
ty
Com
pare
to S
tum
m &
M
orga
n’s
fig. 6
.8c,
pg.
273
David Reckhow CEE 680 #37 9pH0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Log
C
-14
-13
-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
H+
OH-
Zn+2
Zn(OH)4-2
ZnOH+
Zn(OH)2 (aq)
Zn2(OH)6-2
ZnTotal
Zn(OH)3-
Zn2(OH)+3
Zn(OH)2
David Reckhow CEE 680 #37 10
Stumm & Morgan, 1996, Figure 7.6a, pg. 370
ZnO solubility
With oxalate 10-4 M
David Reckhow CEE 680 #37 11
Stumm & Morgan, 1996, Figure 7.6b, pg. 370
ZnO solubility
David Reckhow CEE 680 #37 12pH0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Log
C
-14
-13
-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
H+ OH-
Fe+3 Fe(OH)4-
FeOH+2
Fe(OH)2+
Fe2(OH)2+4
FeTotal
Fe with EDTA
10-8 M EDTA Elevates
solubility in mid-pH range
David Reckhow CEE 680 #37 13
Stumm & Morgan, 1996, Figure 7.7a, pg. 371
Fe with EDTA & Ca
10-8 M EDTA 10-2 M Ca
Mostly counteracts affect of EDTA
David Reckhow CEE 680 #37 14
Stumm & Morgan, 1996, Figure 7.7b, pg. 371
To next lecture
David Reckhow CEE 680 #37 15