scholarly journals Micro-crystalline structure of platinum

1902 ◽  
Vol 69 (451-458) ◽  
pp. 433-435
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Crystalline Structure ◽  
Aqua Regia ◽  
Pure Platinum ◽  
Small Ingot

The crystalline structure of platinum does not appear to have been studied, although it forms an interesting subject for investigation. A small ingot of pure platinum was obtained for the experiments. A section was cut therefrom and machined to 5/16 inch square and 1/10 inch in thickness. The section was then carefully polished and etched in aqua regia of the following strength :— 4 parts of hydrochloric acid (sp. gr. 1·2). 1 part of nitric acid (sp. gr. 1·42).

How aqua regia overcomes the chemical inertness of cinnabar: a thermodynamic analysis in light of long-term knowledge about a reaction that has been of interest for centuries

2019 ◽  
Vol 39 (4) ◽  
pp. 223-231
Author(s):  
Aliyar Mousavi
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Thermodynamic Analysis ◽  
16Th Century ◽  
Aqua Regia ◽  
Sulfide Ion ◽  
Elemental Chlorine ◽  
Chemical Inertness

AbstractWith the rise of the Swiss-born alchemist Paracelsus in the 16th century, the dissolution of cinnabar (red HgS) in aqua regia has repeatedly appeared in the chemical literature. This article reviews the relevant history and takes a thermodynamic approach to shed new light on the dissolution. The conclusions reveal that the reaction in which the sulfide ion is oxidized by nitric acid is the most thermodynamically favorable step in the dissolution. The importance of the role of hydrochloric acid in the dissolution, when it provides complexation, was also observed. Further, it was found that the overall effect of nitric acid is much greater than that of the aqua regia by-product elemental chlorine.

Extraction of iron, cobalt, nickel and copper with dibenzyl sulfoxide solution in toluene

1979 ◽  
Vol 44 (7) ◽  
pp. 2024-2031 ◽  
Author(s):  
František Vláčil ◽  
Huynh Dang Khanh
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Distribution Ratio ◽  
Separation Factor ◽  
Chromatographic Separation ◽  
The Other ◽  
Iron Cobalt ◽  
Cobalt Nickel ◽  
Factor Α

The dependence of the distribution ratio of the metal on the concentration of hydrochloric of nitric acid was examined for Fe, Co, Ni and Cu extraction with 0.05M solution of dibenzylsulfoxide in toluene. Iron is extracted considerably more than the other metals, and is better extracted from hydrochloric acid than from nitric acid. The separation factor αFe/M (for 8M-HCl) is of the order of 104; this is not sufficient for a separation of trace quantities of iron from Co, Ni and Cu, but even at lower concentrations of HCl (e.g., 5M) the values is high enough for extraction chromatographic separation. The composition of the iron solvate extracted from HCl or LiCl medium was determined to be HFeCl4.2 B (B = dibenzyl sulfoxide).

DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

1960 ◽  
Vol 38 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
E. J. Bounsall ◽  
W. A. E. McBryde
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Silver Content ◽  
Aqueous Sodium Chloride Solution ◽  
Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

Rapid Preparation of Cross-Sectional TEM Samples from Electroplated Copper

1990 ◽  
Vol 199 ◽  
Author(s):  
T. E. Dinan ◽  
D. Landolt ◽  
P Ruterana ◽  
P.-A. Buffat
Keyword(s):  
Nitric Acid ◽  
Nickel Alloy ◽  
Crystalline Structure ◽  
Rapid Preparation ◽  
Cross Sectional ◽  
Copper Nickel ◽  
Area Of Interest ◽  
Copper Nickel Alloy ◽  
Electroplated Copper ◽  
Copper Electropolishing

ABSTRACTMethods were investigated for the rapid preparation of cross-sectional TEM samples from electroplated copper. Electropolishing and ultramicrotomy were used. The electropolished samples were sandwiched in a copper/nickel alloy and electropolished using a nitric acid/methanol mixture. Large transparent areas were obtained and it was possible to position the area of interest at the point where the hole would appear. Ultramicrotomed samples cut with 45° diamond knives were electron transparent but the crystalline structure of the sample was severely damaged. However, it was possible to identify the conditions by which good ultramicrotomed samples might be produced in the future.

New reaction for free hydrochloric acid

1906 ◽  
Vol 6 (1) ◽  
pp. 58-58
Author(s):  
F. Simon
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Gastric Juice ◽  
Free Hydrochloric Acid ◽  
Blue Coloration

For the discovery of free hydrochloric acid in gastric juice, Dr. Simon proposes a new reaction based on the properties of guaiac gum to oxidize in the presence of various oxidants (for example, nitric acid) and give a characteristic blue coloration.

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