28.12.2013 Views

preface to fifteenth edition

preface to fifteenth edition

preface to fifteenth edition

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

11.86 SECTION 11<br />

TABLE 11.29<br />

Equations for the Redox Determinations of the Elements with Equivalent Weights (Continued)<br />

Fe(III) Fe 3 4SCN Fe(SCN) 4 ; Fe(SCN) 4<br />

Ti(III) Fe 2 Ti(IV) 4SCN <br />

Fe/1 55.847; Fe 2 O 3 /2 79.845<br />

2Fe 3 Zn 2Fe 2 Zn 2 ; then proceed by a method under Fe(II).<br />

Fe 3 Ag Cl Fe 2 AgCl; then proceed by a method under Fe(II).<br />

2Fe 3 SnCl 2 (slight excess) 4Cl 2Fe 2 2<br />

SnCl 6<br />

2 HgCl 2 SnCl 2 2Cl 2<br />

Hg 2 Cl 2 SnCl 6<br />

Pour above mixture in<strong>to</strong> an H 3 PO 4 plus MnSO 4 solution and titrate with KMnO 4 as under<br />

Fe(II).<br />

Fe/1 55.847; Fe 2 O 3 /2 79.845<br />

2Fe 3 2I Fe 2 I 2<br />

Titrate liberated iodine with thiosulfate; Fe/1 55.847; Fe 2 O 3 /2 79.845<br />

I 2 I 2 2 2I 2<br />

2SO 2 3 SO 4 6 [titrate solution (pH 7.0) with thiosulfate until color is pale<br />

yellow. Add KI and starch and continue titration <strong>to</strong> disappearance of blue color. I 2 /2 <br />

126.9045<br />

I 2 H 3 AsO 3 H 2 O 2I H 3 AsO 4 2H ; use starch and KI as indica<strong>to</strong>r. I 2 /2 <br />

126.9045<br />

I <br />

2I Br 2 (excess) I 2 2Br <br />

Remove excess Br 2 formic acid and titrate I 2 with thiosulfate. I 2 /2 126.9045<br />

<br />

<br />

IO 3 5I (excess) 6H 3I 2 3H 2 O; titrate I 2 with thiosulfate. KIO 3 /6 35.67<br />

<br />

IO 4<br />

IO 3<br />

<br />

IO 4thiosulfate. 7I (excess) 8H 4I 2 4H 2 O; use a neutral buffered solution. Titrate I 2 with<br />

KIO4 /2 115.00<br />

K<br />

K 2 Na[Co(NO 2 ) 6 ]; dissolve in H 2 SO 4 and titrate with either KMnO 4 or Ce(IV). ca. K/5.5 but<br />

use an empirical fac<strong>to</strong>r.<br />

Mg<br />

Mg(oxine) 2 ; dissolve precipitate and use procedure for Al(8-hydroxyquinoline) 3 . Mg/8 <br />

3.0381<br />

Mn(II) 2 Mn 2 5 14H <br />

BiO3 2 MnO4<br />

5Bi 3 7H 2 O<br />

3<br />

2 5 6H 2Mn 2 3<br />

MnO AsO 5 AsO 3H 2 O; Mn/5 10.9876<br />

Mn(IV)<br />

4 3 4<br />

2Mn 2 5 SO 2 2 8 8H 2 O(Ag catalyst) 2 MnO4 10 SO4<br />

2 16H <br />

Titrate the permanganate formed with iron(II) as under iron(II); Mn/5 10.9876<br />

2Mn 2 5 IO4 3H 2 O 2 MnO4 5 IO3<br />

6H <br />

Slowly precipitate excess KIO 4 with Hg(NO 3 ) 2 . Filter, add excess Fe 2 and titrate excess with<br />

standard KMnO 4 solution; Mn/5 10.9876<br />

<br />

4Mn 2 2 3<br />

MnO4 15 HPO 2 2 7 [pH range 4 <strong>to</strong> 7] 5 Mn(HPO) 2 2 7 3 4H 2 O<br />

Use Pt9SCE indica<strong>to</strong>r system; Mn/1 54.9380<br />

MnO 2 2Fe 2 (excesss standard) 4H Mn 2 2Fe 3 2H 2 O (use CO 2 atmosphere)<br />

MnO 2 H 2 C 2 O 4 (excess standard) 2H Mn 2 2CO 2 2H 2 O (use CO 2 atmosphere)<br />

In either of the above, titrate excess with KMnO 4 . Mn/2 27.469; MnO 2 /2 43.47<br />

2<br />

Mn(VI) MnO 2H 2 C 2 O 4 4H Mn 2 4<br />

4CO 2 4H 2 O Add excess oxalate and back-titrate<br />

with permanganate. Mn/4 13.7345<br />

<br />

Mn(VII) 2 MnO 5H 2 C 2 O 4 6H 2Mn 2 4<br />

10CO 2 3H 2 O; Mn/5 10.9876<br />

Mo<br />

Mo(VI) Zn Mo(III) Zn 2 ; catch eluate in excess Fe 2 (SO 4 ) 3 solution<br />

Mo(III) 3Fe 3 2<br />

4H 2 O MoO 3Fe 2 8H 4<br />

; titrate Fe(II) with KMnO 4<br />

Mo/3 31.98<br />

Mo(VI) Ag Cl Mo(V) AgCl; pass through Ag reduc<strong>to</strong>r at 60–80C.<br />

Mo(V) Ce(IV) Mo(VI) Ce(III); Mo/l 95.94<br />

<br />

N 2 H 4 3N 2 H 4 2 BrO (excess) 3N 2 2Br 3<br />

6H 2 O; add excess KI and titrate I 2 with thiosulfate.<br />

N 2 H 4 /4 8.01<br />

<br />

NH 2 OH NH 2 OH BrO3 NO3<br />

Br H H 2 O; proceed as above for N 2 H 4 .NH 2 OH/6 <br />

5.505

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!