Total Acidity as Nitric Acid

Tolyltetrazolonimide. See under Amino-tolyltetrazoles A265-R Total Acidity as Nitric Acid A88-R Total Acidity as Sulfuric Acid A89-L Total Actual Acidity ApO-L Total Nitric as Nitric Acid A88 A89 Total Sulfuric as Sulfuric Acid A89 Transannular Photoperoxide of Anthracene A458-R... 

Quantitative Analysis. The total acidity of nitric acid solution may be deterrnined by conventional titration using phenolphthalein as the indicator. 

Ferrous Sulfdte Titration. For deterrnination of nitric acid in mixed acid or for nitrates that are free from interferences, ferrous sulfate titration, the nitrometer method, and Devarda s method give excellent results. The deterrnination of nitric acid and nitrates in mixed acid is based on the oxidation of ferrous sulfate [7720-78-7] by nitric acid and may be subject to interference by other materials that reduce nitric acid or oxidize ferrous sulfate. Small amounts of sodium chloride, potassium bromide, or potassium iodide may be tolerated without serious interference, as can nitrous acid up to 50% of the total amount of nitric acid present. Strong oxidizing agents, eg, chlorates, iodates, and bromates, interfere by oxidizing the standardized ferrous sulfate. 

EDS II testing revealed the need to monitor nitric acid concentration as well as total acid concentration in the catholyte circuit to prevent formation of silver deposits that led to arcing to the cell membrane and the development of holes in the membrane. More changes may be necessary to maintain the higher nitric acid concentrations in the catholyte. 

Electrolyte chemistries continue to be discovered and need to be carefully controlled, e.g., there is a need to track nitric acid molarity as well as total acid molarity in the catholyte to avoid silver deposition, and the deposition of lead dioxide on cell electrodes and in electrode cavities, which has required the development of a formic acid wash. 

ASM—actual sulfuric as nitric, ASS—actual sulfuric as sulfuric,MA—mixed acid,N normality of std soln,N A—nitric acid, N-so—nitroso, R-burette reading,SA—sulfuric acid.TA— total acidity, TAA-total actual acidity (the sum of actual sulfuric, actual nitric and actual nitroso),TAN—total acidity as nitric,... 

TAS—total acidity as sulfuric,TNN—total nitric as nitric.TNS-total nitric as sulfuric,... 

Dehydrating Value of Sulfuric (DVS) in Mixed Acids. In the process of nitration of aliphatic alcohols (such as glycerin, glycols, etc), it is necessary to know the exact composition of the nitrating acid. In the analysis of such acid, known as mixed acid (MA), the vollowing values must be detd TA (total acidity), TS (total sulfuric), IN (total nitric), AS (actual sulfuric),... 

Unfiltered and unpreserved groundwater water samples collected for total and dissolved metal analyses arrived to the laboratory in a cooler with ice three days after collection. On the fourth day after collection the laboratory filtered the samples for dissolved metal analysis and preserved all samples with nitric acid. The violation of the preservation requirements (no acid ice instead of ambient storage temperature) had a marginal effect on the concentrations of total metals as the addition of acid dissolved most of the metals that may have precipitated in the sample container. That is why the chemist accepts the total metal results, but qualifies them as estimated data. However, because improper preservation and storage have grossly compromised dissolved metal concentrations, the chemist rejects the dissolved metal results and requests that the water be resampled and reanalyzed. 

In addition to ice formation, salts also precipitate as these solutions are lofted to higher altitudes. A consequence of the formation of these solid phases (ice and salts) and the low-temperature eutectics of strong acids (Fig. 3.5) is that the atmospheric solutions become more and more acidic with altitude (Fig. 5.8). For example, the final elevation (temperature) examined is 11.54 km (—50 °C). At this point, the calculated concentrations of the Hubbard Brook solution are H+ = 7.55m with acid anions (Cl-, NO3, SO4-, HSOJ) = 7.91m. Similarly, for the Mt. Sonnblick solution, H+ = 6.50 m and acid anions = 6.90 m. These acidic trends are in line with stratospheric chemistries, which are predominantly sulfuric/nitric acid aerosols (Carslaw et al. 1997). For example, the total acid concentration at 20.7km in the stratosphere is 10.17m (calculated from fig. 7 in Carslaw et al. 1997), which is in line with our lower atmospheric concentrations. 

Analysis. The heating value, ash content, and sulfur distribution of the raw and treated coals were determined according to ASTM procedures (7). Iron in the extracts of the raw and treated coals was determined by titration with a cerium (IV) solution. Iron in the residues from the acid extractions of the raw and treated coals was determined spectrophotometrically using ferrozine (20). The liquid extracts were analyzed for total sulfur (as sulfate) by ion chromatography after separation of the sulfate from nitrate on an alumina column (21). Nitrogen was determined in the raw and treated coal and in their nitric acid-extracted residues by a modified Kjeldahl method. 

The spent acid may also be utilized in a different way, namely by diluting with water to a total acidity of 72-75%, further precipitation of picric acid from the solution may be brought about. After a few days standing, the picric acid is separated from the solution on a vacuum filter, as grade n product. The spent acid thus diluted, after being fortified by adding nitric acid Mid oleum, may be used for the nitration again. 

A number of other delignilicatioii procedures have been devised in which the primary objective has been to obtain, for various purposes, a measure of the total-carbohydrate fraction. These procedures have employed as the active delignifyiiig agents such materials as nitric acid, monoethanola-miiie H. 178 other amines, neutral hypochlorite, acid hypochlorite, etc. These methods have recently been discussed by Browning and by Jahn. Although such procedures are of general interest, their application has not yielded much information that could be considered fundamental to an understanding of the chemistry of wood cellulose. Neither have these procedures become important in the commercial production of wood cellulose. 

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