Lee H. Kalbus

Potentiometric determination of silver with dithiooxamide

Abstract Potentiometric titration with dithiooxamide solution can be used to determine silver in the 0.0100–50.0 p.p.m range with an average accuracy of ca . 0.5% and a relative standard deviation ranging from 1.26% to 0.03% The metals commonly associated with silver can be masked with fluoride and EDTA The advantages of the method over other potentiometric and common spectrophotometric methods are outlined.

The potentiometric titration of silver and copper with dithiooxamide

Abstract Potentiometric titration with dithiooxamide solution can be used to determine silver and copper in mixtures ranging from 1 to 99% silver with a relative standard deviation ranging from 0.16 to 2.00% for silver and from 0.20 to 1.34% for copper. Analysis of twelve different unknown mixtures of silver (0.100–64.0 p.p.m.) and copper (8.00–1.00 p.p.m.) gave an average accuracy of 1.21 % for silver and 0.82% for copper. Interferences from a number of metals commonly associated with silver and copper are discussed. The advantages of the method over other methods for simultaneously determining silver and copper in a sample are outlined.

Potentiometric determination of mercury(II) with dithiooxamide

Potentiometric titration with dithiooxamide can be used to determine mercury in the 0·10 to 40·0 p.p.m. range (0·01 mg to 4·00 mg per 100 ml) with a relative standard deviation ranging from 1·50 to 0·26 per cent. and an accuracy of about 0·3 per cent. A silver indicator electrode is used. Several interferences were investigated and found to have little effect. Among these were cadmium, zinc, nickel, iron, lead and cobalt. The interferences of silver and copper in the determination were also investigated and are discussed. Two simple fast modifications to the procedure are suggested when determining mercury in the presence of either silver or copper. The advantages of this method over other methods are outlined.

Anomalies in the Infrared Spectra of Mixed Carbonate Precipitates

When a mixture of cations in solution is precipitated by the addition of carbonate, the resulting mixed carbonate precipitate, when subjected to infrared examination, does not usually exhibit the individually characteristic absorption bands due to each of the carbonates constituting the mixture. Instead, various interesting anomalies such as blending of bands, shifting of positions, and changing of intensities are observed. Such anomalous behavior may hamper any qualitative or quantitative measurements on such samples. Representative spectra and possible explanations for some of these anomalies are presented.

A simple molecular weight experiment

The authors share a method that is conceptually similar to the Dumas method and students have had considerable success.

Use of infrared spectrophotometry in the analysis of limestone

This paper reports an exploration and extension of the usefulness of infrared as a teaching aid in the field of inorganic analytical chemistry. Includes sample spectra and their analysis.