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Title: Rapid potentiometric determination of carbonates in the presence of sulfides, cyanides and free ammonia

Abstract

Carbon dioxide in aqueous solutions may be present in the undissociated form, and also in the form of hydrocarbonate and carbonate ions. Coking plant liquors, containing free NH/sub 3/ (the ammonia and supernatant liquors), have a pH of 9 to 10. Under these conditions the concentration of free CO/sub 2/ is negligible and its principal form of existence is as hydrocarbonate ions. CO/sub 2/ in coking plant liquors is usually determined by a prolonged and laborious method based on separation of the carbonates by precipitation. The use of such a complex method is a result of the simultaneous presence of S/sup 2 -/, HS/sup 1 -/, CN/sup 1 -/, S/sub 2/O/sub 3//sup 2 -/, HCN and H/sub 2/S and other ions and molecules, which interfere with simple acidimetric determination of the carbonate. It is of interest to determine the possibility of acidimetric determination of HCO/sub 3//sup 1 -/ after titration of S/sup 2 -/ and CN/sup 1 -/ with an Hg(NO/sub 3/)/sub 2/ solution, during which the S/sup 2 -/ and HS/sup 1 -/ are removed from the solution in the form of a low-solubility HgS precipitate, and the CN/sup 1 -/ is fixed in a low-dissociation Hg(CN)/sub 2/ complex.more » Figure 2 shows curves of the comparative pH-metric titration (a) with glass and silver chloride electrodes and potentiometric titration (b) with a bimetallic pair of platinum-tungsten electrodes of a model solution containing 2 ml of 0.1 N NH/sub 3/.H/sub 2/O and 3 ml of 0.1 N NH/sub 4/HCO/sub 3/ with a 0.1 N solution of HNO/sub 3/. Both pairs of electrodes may be used to indicate the final titration points of NH/sub 3/H/sub 2/O and HCO/sub 3//sup 1 -/. Hydrochloric acid may be used as the titration solution.« less

Authors:
; ;
Publication Date:
OSTI Identifier:
5632727
Resource Type:
Journal Article
Journal Name:
Coke Chem. USSR (Engl. Transl.); (United States)
Additional Journal Information:
Journal Volume: 4; Other Information: Translated from Koks Khim.; No. 4, 34-36(1980)
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CARBONATES; POTENTIOMETRY; COKING PLANTS; WASTE WATER; CHEMICAL ANALYSIS; EXPERIMENTAL DATA; CARBON COMPOUNDS; DATA; HYDROGEN COMPOUNDS; INDUSTRIAL PLANTS; INFORMATION; LIQUID WASTES; NUMERICAL DATA; OXYGEN COMPOUNDS; TITRATION; WASTES; WATER; 010500* - Coal, Lignite, & Peat- Products & By-Products; 400100 - Analytical & Separations Chemistry

Citation Formats

Dyatel, G S, Teikhrib, T K, and Kusova, A I. Rapid potentiometric determination of carbonates in the presence of sulfides, cyanides and free ammonia. United States: N. p., 1980. Web.
Dyatel, G S, Teikhrib, T K, & Kusova, A I. Rapid potentiometric determination of carbonates in the presence of sulfides, cyanides and free ammonia. United States.
Dyatel, G S, Teikhrib, T K, and Kusova, A I. Tue . "Rapid potentiometric determination of carbonates in the presence of sulfides, cyanides and free ammonia". United States.
@article{osti_5632727,
title = {Rapid potentiometric determination of carbonates in the presence of sulfides, cyanides and free ammonia},
author = {Dyatel, G S and Teikhrib, T K and Kusova, A I},
abstractNote = {Carbon dioxide in aqueous solutions may be present in the undissociated form, and also in the form of hydrocarbonate and carbonate ions. Coking plant liquors, containing free NH/sub 3/ (the ammonia and supernatant liquors), have a pH of 9 to 10. Under these conditions the concentration of free CO/sub 2/ is negligible and its principal form of existence is as hydrocarbonate ions. CO/sub 2/ in coking plant liquors is usually determined by a prolonged and laborious method based on separation of the carbonates by precipitation. The use of such a complex method is a result of the simultaneous presence of S/sup 2 -/, HS/sup 1 -/, CN/sup 1 -/, S/sub 2/O/sub 3//sup 2 -/, HCN and H/sub 2/S and other ions and molecules, which interfere with simple acidimetric determination of the carbonate. It is of interest to determine the possibility of acidimetric determination of HCO/sub 3//sup 1 -/ after titration of S/sup 2 -/ and CN/sup 1 -/ with an Hg(NO/sub 3/)/sub 2/ solution, during which the S/sup 2 -/ and HS/sup 1 -/ are removed from the solution in the form of a low-solubility HgS precipitate, and the CN/sup 1 -/ is fixed in a low-dissociation Hg(CN)/sub 2/ complex. Figure 2 shows curves of the comparative pH-metric titration (a) with glass and silver chloride electrodes and potentiometric titration (b) with a bimetallic pair of platinum-tungsten electrodes of a model solution containing 2 ml of 0.1 N NH/sub 3/.H/sub 2/O and 3 ml of 0.1 N NH/sub 4/HCO/sub 3/ with a 0.1 N solution of HNO/sub 3/. Both pairs of electrodes may be used to indicate the final titration points of NH/sub 3/H/sub 2/O and HCO/sub 3//sup 1 -/. Hydrochloric acid may be used as the titration solution.},
doi = {},
url = {https://www.osti.gov/biblio/5632727}, journal = {Coke Chem. USSR (Engl. Transl.); (United States)},
number = ,
volume = 4,
place = {United States},
year = {1980},
month = {1}
}