Laboratory manual for the course in advanced quantitative analysis

by Hobart H. Willard

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated.1920 ... vanadyl salt is then oxidized by adding just the right amount of KMn0. and titrated as before with standard FeS04. (Kelley and Conant, J. Amer, Chem. Soc. 38, 34l; J. Ind, Eng. Chem. 8, 7l9). 0r the vanadyl salt is oxidized by boiling with 40 cc of conc. HN0j for l hour, tkking care that the volume does not fall below l00 cc. No Cr is oxidized under these conditions; the oxidation of V is practically complete, amounting to 99$. The vanadic acid is then titrated with FeS04, keeping the solution as cold as possible. (Kelley, J. Ind. Eng. Chem. ll,632). OTHER LESS IMP0RTANT METH0DS F0R DETERMINING VANADIUM. (l) The Fe is separated by an ether extraction, the solution oxidized, then the HV03 reduced by evaporation with HCl, after which the HCl is removed by evaporation with HgS04 and the V0S04 titrated with permanganate. (2) After the ether extraction the solution is evaporated with HN03 nearly neutralised and poured into hot Na0H. The ppt. is dissolved and the treatment repeated until all V is removed, several operations often being required. The Cr remains in the ppt. tho traces usually dissolve. The Na3V04 is pptd. by HgN03 ignited to Vg0e, dissolved, reduced and titrated. 0r, it may be pptd. as Pd vanadate, dissolved in H2S04, reduced and titrated. (3) The V is oxidized by KMh04, the excess being removed by FeS04, A slight excess of standard FeS04 is added and titrated back with KgCr207, using ferricyanide indicator. The disadvantagesof the latter has already been mentioned. (4) V may be separated from Cr, U, Al, Mn, Zn, Co, Ni; by pption. with "Cupferron" (ammon. nitrosoptienylhydroxylamine). Turner, Amer. Jour. Sci, 4l, 339; 42, l09 (l9l6). 0ther references on the determination of V in ores, Bleecker, Met. Chem. Eng. 8, 666, and 9, 209; Goods and Gi...

352 pages, Paperback

Published January 1, 1920