PRACTICAL |
LABORATORY |
INFORMATION |
|
|
11.67 |
|||
TABLE 11.19 Gravimetric Factors ( |
Continued |
|
|
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Factor |
|
|
|
|
|
|
|
Factor |
|
|
|
|
|
|
|
|
|
|
|
|
|
ZIRCONIUM |
|
|
|
|
|
|
|
|
|
Zr 91.22 |
|
|
|
2.4864 |
K |
2 |
ZrF |
6 |
4 F |
|
|
0.40219 |
2.4390 |
K |
2 |
ZrF |
6 |
4 2KF |
|
|
0.41001 |
1.5054 |
K |
2 |
ZrF |
6 |
4 2(KF · 2H |
2 O) |
0.66427 |
|
3.1069 |
K |
2 |
ZrF |
6 |
4 Zr |
|
|
0.32187 |
2.3000 |
K |
2 |
ZrF |
6 |
4 ZrO |
2 |
|
0.43478 |
8.5946 |
|
ZrC |
|
4 C |
|
|
0.11635 |
|
2.2004 |
|
ZrF |
|
4 |
4 F |
|
|
0.45447 |
1.3508 |
|
ZrO |
|
2 |
4 Zr |
|
|
0.74030 |
0.46470 |
|
ZrO |
|
2 |
4 ZrP |
2 O |
7 |
2.1519 |
TABLE 11.20 Elements Precipitated by General Analytical Reagents
This table includes the more common reagents used in gravimetric determinations. The lists of elements precipitated are not in all cases exhaustive. The usual solvent for a precipitating agent is indicated in parentheses after its name or formula. When the symbol of an element or radical is italicized, the element may be quantitatively determined by the use of the reagent in question.
|
|
Reagent |
|
|
Conditions |
Substances precipitated |
|
|||||||
|
|
|
|
|
|
|
|
|
||||||
Ammonia, NH |
3 |
(aqueous) |
|
After removal of acid sulfide |
Al , Au, Be |
, Co, Cr , Cu, |
Fe, |
Ga, |
||||||
|
|
|
|
|
|
|
group. |
In, |
Ir, La |
, Nb, Ni, Os, P, |
Pb, |
|||
|
|
|
|
|
|
|
|
rare earths, |
Sc, |
Si, Sn, |
Ta, Th, |
|||
|
|
|
|
|
|
|
|
Ti, |
U, |
V, Y, Zn, |
Zr |
|
|
|
Ammonium polysulfide, |
|
|
After removal of acid sulfide and |
Co, Mn, Ni, Si, Tl, V, W, Zn |
|
|||||||||
(NH |
4 )2 S x |
(aqueous) |
|
|
(NH 4 )2 S groups. |
|
|
|
|
|
|
|
||
Anthranilic acid, NH |
2 C 6 H |
4 COOH |
|
1% aqueous solution (pH 6); Cu |
Ag, |
Cd, |
Co, Cu, |
Fe, Hg, Mn, |
Ni, |
|||||
(aqueous) |
|
|
|
|
separated from others at pH |
Pb, |
Zn |
|
|
|
|
|
||
|
|
|
|
|
|
|
2.9. |
|
|
|
|
|
|
|
-Benzoin oxime, |
|
|
(a) Strongly acid medium. |
(a) Cr(VI), |
Mo(VI) |
, Nb, Pd(II), |
||||||||
C 6 H |
5 CHOHC( |
|
|
"NOH)C |
6 H |
5 |
|
Ta(V), V(V), |
W(VI) |
|
|
|||
(1– 2% alcohol) |
|
|
|
(b) Ammoniacal tartrate medium. |
(b) Above list |
|
|
|
||||||
Benzidine, H |
2 NC |
|
6 H 4 C 6 H |
4 NH |
2 |
|
Cd, Fe(III), |
|
3 |
SO |
2 |
|||
|
|
IO ,3 |
PO 4 , |
4 , |
||||||||||
(alcohol), 0.1 |
M |
HCl |
|
|
|
W(VI) |
|
|
|
|
|
|||
N -Benzoylphenylhydroxylamine, |
Similar to cupferron ( q.)v..Cu, |
See Cupferron |
|
|
|
|||||||||
C 6 H |
5 CO(C |
6 H |
5 )NOH (aqueous) |
Fe(III), and Al complexes can |
|
|
|
|
|
|
|
|||
|
|
|
|
|
|
|
be weighed as such; Ti com- |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
pound must be ignited to the |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
oxide. |
|
|
|
|
|
|
|
Cinchonine, C |
19 |
H 21 N 2 OH, 6 |
M |
HCl |
|
|
|
Cupferron, C |
6 H |
5 N(NO)ONH |
4 |
(aqueous)
1,2-Cyclohexanedionedioxime
Group precipitant for several higher-charged metal ions from strongly acid solution.
Precipitate ignited to metal oxide.
More water soluble than dimethylglyoxime; less subject to coprecipitation with metal chelate.
Ir, Mo, Pt, W |
|
|
Al, Bi, Cu, Fe, Ga, |
La, Mo, Nb |
, |
Pd, rare earths, Sb, Sn , Ta, |
Th, |
|
Ti, Tl, U, V |
, W, Zr |
|
See Dimethylglyoxime
11.68 |
|
|
|
|
|
|
SECTION |
11 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
TABLE 11.20 |
Elements Precipitated by General Analytical Reagents ( |
Continued |
|
|
) |
|
|
|
|
|
|
|
|
|
|
|
||||||||
|
|
|
|
|
|
|
|
|||||||||||||||||
|
Reagent |
|
Conditions |
|
Substances precipitated |
|
|
|||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|||||||||||||||
Diammonium hydrogen phos- |
(a) Acid medium. |
|
(a) |
Bi, Co |
|
, Hf, In, Ti, |
Zn, Zr |
|
|
|||||||||||||||
phate, (NH |
4 ) 2 HPO |
4 |
(aqueous) |
(b) Ammoniacal medium con- |
(b) Au, Ba, |
|
Be |
, Ca, Hg, In, La, |
||||||||||||||||
|
|
|
|
|
|
taining citrate or tartrate. |
|
Mg, |
Mn |
|
, Pb, rare earths, Sr, |
|||||||||||||
|
|
|
|
|
|
|
|
|
|
|
Th, U, |
Zr |
|
|
|
|
|
|
|
|
|
|||
Dimethylglyoxime, |
|
|
|
(a) Dilute HCl or H |
2 SO 4 me- |
(a) Au, |
|
Pd |
, Se |
|
|
|
|
|
|
|
||||||||
[CH |
3 C(NOH)] |
|
2 (alcohol) |
dium. |
|
|
|
(b) |
Ni |
|
(and Co, Fe if present in |
|||||||||||||
|
|
|
|
|
|
(b) Ammoniacal tartrate medium |
|
large amounts) |
|
|
|
|
|
|
||||||||||
|
|
|
|
|
|
about pH 8. Weighed as such. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
Hydrazine, N |
2 H 4 |
(aqueous) |
|
|
|
|
Ag, Au, |
Cu, Hg |
|
, Ir,Os , Pd, Pt, |
||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
Rh |
, Ru, Se, |
Te |
|
|
|
|
|
|
|
||||
Hydrogen sulfide, H |
2 S |
(a) 0.2– 0.5 |
M |
H . |
(a) Ag, |
|
|
As, |
Au, Bi, Cd, |
|
Cu, |
Ge, |
||||||||||||
|
|
|
|
|
|
|
|
|
|
|
Hg, |
|
In, Ir, Mo |
, Os, Pb, Pd, Pt , |
||||||||||
|
|
|
|
|
|
|
|
|
|
|
Re, |
Rh, Ru, Sb, Se, Sn, Te, Tl, |
||||||||||||
|
|
|
|
|
|
|
|
|
|
|
V, W, Zn |
|
|
|
|
|
|
|
|
|
||||
|
|
|
|
|
|
(b) Ammoniacal solution after re- |
(b) Co, Fe, Ga, In, Mn, Ni, Tl, |
|
||||||||||||||||
|
|
|
|
|
|
moval of acid sulfide group. |
|
U, V, Zn |
|
|
|
|
|
|
|
|
|
|||||||
4-Hydroxyphenylarsonic acid, |
Dilute acid solution. |
Ce,Fe, |
Sn, |
Th |
|
, Ti, |
Zr |
|
|
|
|
|
||||||||||||
C 6 H |
4 (OH)AsO(OH) |
|
|
2 (aqueous) |
|
|
buffer. |
(a) Ag, |
|
|
|
, Bi, Cd, |
|
|
|
Cr, |
|
|
||||||
8-Hydroxyquinoline (oxine), |
(a) HOAc– OAc |
|
|
|
Al |
Co, |
|
|
Cu, |
|||||||||||||||
C 9 H |
6 NOH, (alcohol) |
|
|
|
|
|
|
|
Fe, |
|
Ga, Hg, |
|
In, |
La, |
Mn, Mo |
|
, |
|||||||
|
|
|
|
|
|
|
|
|
|
|
Nb, |
|
Ni |
, Pb, Pd, rare earths, Sb, |
||||||||||
|
|
|
|
|
|
|
|
|
|
|
Ta, Th, Ti, V, W, |
Zn, |
|
Zr |
|
|
||||||||
|
|
|
|
|
|
(b) Ammoniacal solution. |
(b) Same as in (a) except for Ag; |
|||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
in addition, Ba, |
Be, |
Ca, |
Mg, |
|
|
||||||||
|
|
|
|
|
|
|
|
|
|
|
Sn, Sr |
|
|
|
|
|
|
|
|
|
|
|||
2-Mercaptobenzothiazole, |
Ammoniacal solution, except for |
Ag, |
Au, |
Bi, |
Cd, |
Cu, |
|
Hg, |
Ir, Pb, |
|||||||||||||||
C 6 H |
4 (SCN)SH (acetic acid so- |
Cu, when a dilute acid solution |
|
Pt, |
Rh |
, Tl |
|
|
|
|
|
|
|
|
||||||||||
lution) |
|
|
|
|
is used. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
||
Nitron (diphenylenedianilohydro- |
Dilute H 2 SO |
4 |
medium. |
B, |
ClO |
|
|
|
|
|
|
, |
|
4 |
|
W |
||||||||
,3 |
ClO |
, NO4 |
, ReO3 |
|
|
|||||||||||||||||||
triazole), C20 H |
16 N |
4 |
, (5% acetic |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
||
acid) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1-Nitroso-2-naphthol, |
|
Selective for Co; acid solution. |
Ag, Au, B, |
|
Co, |
Cr, Cu, Fe |
, Mo, |
|||||||||||||||||
C 10 H |
6 (NO)OH (very dilute al- |
Precipitate ignited to Co 3 O 4 . |
|
Pd, Ti, V, W, Zr |
|
|
|
|
|
|
||||||||||||||
kali) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Oxalic acid, H |
2 C 2 O |
4 , (aqueous) |
Dilute acid solution. |
Ag, |
Au, |
|
|
Cu, |
Hg, |
La, |
Ni, |
Pb, rare |
||||||||||||
|
|
|
|
|
|
|
|
|
|
|
earths, |
Sc, Th |
|
|
, U(IV), W, |
|
Zr |
|||||||
Phenylarsonic acid, |
|
|
Selective precipitants for quadri- |
Bi , Ce(IV), Fe, |
|
Hf, Mg, |
Sn, |
Ta, |
|
|
||||||||||||||
C 6 H |
5 AsO(OH) |
|
2 , (aqueous) |
valent metals in acid solution. |
|
Th |
, Ti, U(IV), W, |
|
Zr |
|
|
|
|
|||||||||||
|
|
|
|
|
|
Metals weighed as dioxides. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
Phenylthiohydantoic acid, |
|
|
|
|
Bi, Cd, |
|
Co, Cu, Fe, Hg, Ni, Pb, |
|
||||||||||||||||
C H6 N 5 |
"C(NH )SCH2 COOH |
2 |
|
|
|
|
|
Sb |
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
(aqueous or alcohol) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||||
Picrolonic acid, C |
10 |
H |
7 O 5 N 4 H |
Neutral solution. |
Ca |
, Mg, |
Pb, |
Th |
|
|
|
|
|
|
|
|
||||||||
(aqueous) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Propylarsonic acid, |
|
|
|
Preferred for W; see Phenylar- |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||||
C 3 H |
9 AsO(OH) |
|
2 (aqueous) |
sonic acid. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
Pyridine plus thiocyanate |
Dilute acid solution. |
Ag, Cd, Cu, Mn, Ni |
|
|
|
|
|
|
|
|
|
|||||||||||||
Quinaldic acid, C |
9 B |
6 NCOOH |
Dilute acid solution. |
Ag, Cd, |
|
Co, Cu |
, Fe, Hg, Mo, Ni, |
|||||||||||||||||
(aqueous) |
|
|
|
|
|
|
|
|
|
Pb, Pd, Pt(II), |
U |
, W, |
|
Zn |
|
|
||||||||
Salicylaldoxime, C |
7 H |
5 (OH)NOH |
Dilute acid solution. |
Ag, Bi, |
|
Cd, Co, |
Cu |
, Fe, Hg, Mg, |
||||||||||||||||
(alcohol) |
|
|
|
|
|
|
|
|
|
Mn, Ni, |
Pb, |
Pd |
|
, V, Zn |
|
|
||||||||
Silver nitrate, AgNO |
3 |
(aqueous) |
(a) Dilute HNO |
3 |
solution. |
(a) Br |
, Cl , I , SCN |
|
|
|
|
|||||||||||||
|
|
|
|
|
|
(b) Acetate buffer, pH 5– 7. |
(b) |
As(V) |
|
, CN |
|
,OCN |
|
, IO |
|
|
||||||||
|
|
|
|
|
|
|
|
|
3, |
|
||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
Mo(VI), N |
S 3 , |
2 , V(V) |
|
|
|
||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
PRACTICAL |
LABORATORY INFORMATION |
|
|
|
11.69 |
|
TABLE 11.20 |
Elements Precipitated by General Analytical Reagents ( |
Continued |
) |
|
|||||
|
|
|
|
|
|
||||
|
Reagent |
|
|
Conditions |
Substances precipitated |
||||
|
|
|
|
|
|||||
Sodium tetraphenylborate, |
Specific for K group of alkali |
Cs, K, |
NH , 4 Rb |
|
|||||
NaB(C |
6 H 5 ) 4 |
(aqueous) |
metals from dilute HNO 3 or |
|
|
|
|||
|
|
|
|
HOAc solution (pH 2), or pH |
|
|
|
||
|
|
|
|
6.5 in presence of EDTA. |
|
|
|
||
Tannic acid (tannin), C |
14 H 10 O 9 |
Acts as negative colloid that is a |
Al, Be, |
Cr, Ga, |
Ge , Nb, Sb, Sn, |
||||
(aqueous) |
|
|
flocculent for positively |
Ta, |
Th, Ti, U, |
V, W, Zr |
|||
|
|
|
|
charged hydrous oxide sols. |
|
|
|
||
|
|
|
|
Noteworthy for W in acid so- |
|
|
|
||
|
|
|
|
lution, and for Ta (from Nb in |
|
|
|
||
|
|
|
|
acidic oxalate medium). |
|
|
|
||
Tartaric acid, |
|
|
|
|
|
Ca, K, Mg, Sc, Sr, Ta |
|
||
HOOC(CHOH) |
2 COOH (aque- |
|
|
|
|
|
|
||
ous) |
|
|
|
|
|
|
|
|
|
Tetraphenylarsonium chloride, |
(C 6 H |
5 )4 AsTlCl 4 |
and |
Re, Tl |
|
|
|||
(C 6 H |
5 )4 AsCl (aqueous) |
(C |
6 H 5 )4 AsReO |
4 weighed as |
|
|
|
||
|
|
|
|
such. |
|
|
|
|
|
Thioglycolic- -aminonaphthal- |
(a) Acid solution. |
(a) Ag, As, Au, Bi, |
Cu, Hg, Os, |
||||||
ide, thionalide, |
|
|
|
|
Pb, |
Pd, Rh, Ru |
, Sb, Sn, Tl |
||
C 10 H |
7 NHCOCH |
2 SH (alcohol) |
(b) Carbonate medium containing |
(b) Au, Cd, Cu, Hg(II), Tl(I) |
|||||
|
|
|
|
tartrate. |
|
|
|
|
|
|
|
|
|
(c) Carbonate medium containing |
(c) Au, Bi, Pb, Sb, Sn, Tl |
||||
|
|
|
|
tartrate and cyanide. |
|
|
|
||
|
|
|
|
(d) Strongly alkaline medium |
(d) Tl |
|
|
||
|
|
|
|
containing tartrate and cya- |
|
|
|
||
|
|
|
|
nide. |
|
|
|
|
|
Source: J. A. Dean, ed., Analytical Chemistry Handbook , McGraw-Hill, New York, 1995.
TABLE 11.21 Cleaning Solutions for Fritted Glassware
Material |
Cleaning solution |
|
|
Fatty materials |
Carbon tetrachloride. |
Organic matter |
Hot concentrated sulfuric acid plus a few drops of sodium or potassium nitrate |
|
solution. |
Albumen |
Hot aqueous ammonia or hot hydrochloric acid. |
Glucose |
Hot mixed acid (sulfuric plus nitric acids). |
Copper or iron oxides |
Hot hydrochloric acid plus potassium chlorate. |
Mercury residue |
Not nitric acid. |
Silver chloride |
Aqueous ammonia or sodium thiosulfate. |
Aluminous and siliceous |
A 2% hydrofluoric acid solution followed by concentrated sulfuric acid; rinse |
residues |
immediately with distilled water followed by a few milliliters of acetone. Re- |
|
peat rinsing until all trace of acid is removed. |
|
|
11.70 |
|
SECTION 11 |
|
TABLE 11.22 |
Common Fluxes |
|
|
|
|
|
|
|
|
Types of |
|
|
Melting |
crucible used |
Type of substances |
Flux |
point, C |
for fusion |
decomposed |
Na |
2 |
CO |
3 |
851 |
Na |
2 |
CO |
3 |
plus an oxi- |
|
dizing agent such as |
|||
|
KNO |
3 |
, KClO 3 , or |
|
|
Na |
|
2 O 2 |
|
NaOH or KOH |
320– 380 |
|||
Pt |
|
For silicates, and silica-containing samples; |
|
|
alumina-containing samples; insoluble |
|
|
phosphates and sulfates |
Pt (do not |
For samples needing an oxidizing agent |
|
use with |
|
|
Na |
2 O 2 ) or |
|
Ni |
|
|
Au, Ag, Ni |
For silicates, silicon carbide, certain |
|
|
|
minerals |
Na |
2 O |
2 |
Decomposes |
Fe, Ni |
For sulfides, acid-insoluble alloys of Fe, |
|
|
|
|
|
Ni, Cr, Mo, W, and Li; Pt alloys; Cr, |
|
|
|
|
|
Sn, Zn minerals |
K |
2 S 2 O |
7 |
300 |
Pt or porce- |
Acid flux for insoluble oxides and oxide- |
|
|
|
|
lain |
containing samples |
B 2 O 3 |
|
577 |
Pt |
For silicates and oxides when alkalis are to |
|
|
|
|
|
|
be determined |
CaCO |
3 plus NH 4 Cl |
|
Ni |
For decomposing silicates in the determi- |
|
|
|
|
|
|
nation of alkali element |
|
|
|
|
|
|
TABLE 11.23 |
Membrane Filters |
|
|
|
|
|
|
Filter pore |
Maximum rigid particle |
Filter pore |
Maximum rigid particle |
size, m |
to penetrate, m |
size, m |
to penetrate, m |
|
|
|
|
14 |
17 |
0.65 |
0.68 |
10 |
12 |
0.60 |
0.65 |
8 |
9.4 |
0.45 |
0.47 |
7 |
9.0 |
0.30 |
0.32 |
5 |
6.2 |
0.22 |
0.24 |
3 |
3.9 |
0.20 |
0.25 |
2 |
2.5 |
0.10 |
0.108 |
1.2 |
1.5 |
0.05 |
0.053 |
1.0 |
1.1 |
0.025 |
0.028 |
0.8 |
0.95 |
|
|
|
|
|
|