Determination of oxygen in helium by Winkler's method

✍ Scribed by K.G. Divekar; K.A. Khasgiwale; M. Sundaresan

• Publisher: Elsevier Science
• Year: 1964
• Tongue: English
• Weight: 314 KB
• Volume: 31
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)88823-6

✦ Synopsis

Discussion

Malachite green and methylenc blue may find application in the iodimctric procedure for the determination of weak acids. For example, KAMATH ANI) MAINKAR~ found difficulties with the sensitivity of the starch end-point in the determination of carboxylic acids in lac, since lac is insoluble in water and soluble in alcohol.

Applications may also appear in the iodimetric titration of cyanide in carbonatcbicarbonate medium, where it is not advisable to use starch as indicator, for the reaction between cyanide and iodine is measurably slow, and the addition of starch makes it even slowcr3.

Mcthylcnc blue and especially malachite green seem prcfcrable to starch in titrations with dilute solutions, or in the presence of large amounts of electrolytes or ethanol. In addition to methylcnc blue and malachite green, methyl green has also shown good possibilities as an iodimctric indicator.

School of Engineering

, University of Rio Granda do Sul, P&lo Alepe, R.G.S. (Brazil) J. 0. MEDITSCH * J. A. GAUTILCR, rlwr. IJlrrtrn~. Fmm.. 6 (1948) 171. 2 M. MUTNIANSKI, %. Anal. C/rer,x., 36 (I 897) zzo. 3 I. &I. I<OLTHOPIr AND 13, I3rsr.c11rs~, I'dtcrnrtric ,duulysis, 'ol. III,