By Ross W. Moshier
Read Online or Download Analytical Chemistry of Niobium and Tantalum PDF
Similar general & reference books
The aim of this e-book is to aid chemists, biochemists and different scientists purify the chemical reagents which they use of their paintings. although commercially to be had chemical substances are usually of a really prime quality, and really passable for a few functions inside of technological know-how and know-how, it's changing into nearly as very important to grasp what impurities are current and allow for them as to take away them thoroughly.
Growth in actual natural Chemistry is devoted to reviewing the newest investigations into natural chemistry that use quantitative and mathematical tools. those stories support readers comprehend the significance of person discoveries and what they suggest to the sector as a complete. furthermore, the authors, best specialists of their fields, supply precise and thought-provoking views at the present kingdom of the technological know-how and its destiny instructions.
Content material: bankruptcy I Furopyrans and ? Pyrones (pages 1–13): bankruptcy II Furocoumarins (pages 14–101): bankruptcy III Furochromones (pages 102–159): bankruptcy IV Furoxanthones (pages 160–174): bankruptcy V Furoflavones (pages 175–200): bankruptcy VI The Furoisoflavanoids (pages 201–271): bankruptcy VII Chromanochromanones (The Rotenoids) (pages 272–327): bankruptcy VIII much less universal Furopyrone structures (pages 328–335):
- Ceramic Interfaces - Properties and Applications
- Gas Chromatography: Principles, Techniques, and Applications, Second Edition
- Volume 1, Compendium of Organic Synthetic Methods
- Bioactive Natural Products (Part F), Volume 25 (Studies in Natural Products Chemistry)
- Introduction to Concepts and Theories in Physical Science
Extra resources for Analytical Chemistry of Niobium and Tantalum
TARTRATE HYDROLYSIS FOR PRECIPITATION OF THE MAJOR FRACTION OF THE TANTALIC, NIOBIC AND TUNGSTIC ACIDSd'2) Treat the filtrate after removal of the metals of the hydrogen sulfide group with more hydrogen sulfide to reduce iron to the ferrous condition. This should be done on the filtrate evaporated to 150 ml. Bring the solution to the boil and stir in 25 ml of concentrated hydrochloric acid and continue to boil for 5 min. Niobic acid precipitates immediately but tantalic acid requires a little longer for precipitation.
The tantalum precipitate is not of definite composition. The precipitate therefore cannot be dried and weighed as such, and must be ignited to the oxide. 46 per cent niobium. It dries to constant weight at 110° and can be weighed as such if desired/33^ Procedure III. ^® The combined filtrates and washings from Procedure I contain all of the titanium and zirconium. Evaporate the solution almost to dryness and destroy the pyrogallol by digesting first with fuming nitric acid and then with a mixture of perchloric acid and sulfuric acid.
Cool the melt on the sides of the crucible, dissolve it in 1 g of tartaric acid in 20 ml of water, and dilute with water to volume in a 100 ml volumetric flask. Samples containing 4 per cent or 15 per cent niobium pentoxide are dissolved using 2 g and 5 g of tartaric acid respectively. The solution is now ready for colorimetric analysis. Recommended is the homogenous solution (with acetone) thiocyanate method of Freund and Levitt, with suitable corrections for the interference of iron, titanium and tungsten.