Tested for solubility

Addition of hydrogen peroxide to a solution of a dichromate yields the blue colour of "peroxochromic acid. This is a test for soluble chromates and dichromates. 

Analysis. Specifications and tests for soluble CN have been adopted by ASTM and are described (48,73—75). Brief descriptions of the most important tests are given here. 

Solubility measurement. The general scheme of testing for solubility involves subdivision, exposure, agitation, separation, and measurement ( , 8-21). 

Sodium thiatriazole-5-thiolate gives colored precipitates with copper(II) or bismuth salts. This reaction may be used as a test for soluble inorganic azides by way of their reaction with CS2, which yields thiatriazole-5 -thiolates.47... 

Testing for low levels of silica, iron, copper, etc. may require special sampling techniques (for example, no glass bottles for silica the addition of a small, known volume of HC1 to the sample bottle, when testing for soluble Fe and Cu, prior to taking the sample no metal lids used). 

R7. Rossen, R. D., Reisbert, M. A., Hersh, E. M., and Gutterman, J. U., The Clq binding test for soluble immune complexes Clinical correlations obtained in patients with cancer. J. Natl. Cancer Inst. 58, 1205-1215 (1977). 

Free Alkali Add 2 drops of phenolphthalein TS to 20 mL of diluted filtrate prepared in the test for Soluble Salts (below), representing 1 g of magnesium silicate. If a pink color develops, not more than 2.5 mL of 0.1 N hydrochloric acid discharges it. 

This is a sensitive test for soluble sulphides and hydrogen sulphide. 

CHARACTERIZATION. Melting points were determined on an E. I. DuPont Series 99 Thermal Analyzer at 20°C/min. Inherent viscosities of polyamic acid solutions were obtained at a concentration of 0.5% (w/w) in DMAc at 35°C. Glass transition temperatures (T ) of the fully cured polymer films were measured by thermomechanical analysis (TMA) on a DuPont 943 Analyzer in air at 5°C/min. Films fully-cured at 300°C were tested for solubility at 3-5% (w/w) solids concentration in DMAc,N,N-dimethylformamide (DMF), and chloroform (CHCl-j). Solubilities at room temperature were noted after periods of 3 hours, 1 day and 5 days. Refractive indices of 1 mil thick films were obtained at ambient temperature by the Becke line method (11) using a polarizing microscope and standard immersion liquids obtained from R. P. Cargille Labs. 

Several polymers were tested for solubility at high concentrations of polymer in the solvent. Previous studies had shown that ODPA + o,p -ODA and 6F + o,p -ODA films had a high degree of solubility in DMF at room temperature (>40% w/w). ( )... 

You are to purify 2.0 g of an unknown provided by the instructor. Conduct tests for solubility and ability to crystallize in several organic solvents, solvent pairs, and water. Conserve your unknown by using very small quantities for solubility tests. If only a drop or two of solvent is used the solvent can be evaporated by heating the test tube on the steam bath or sand bath and the residue can be used for another test. Submit as much pure product as possible with evidence of its purity (i.e., the melting point). From the posted list identify the unknown. 

A) Test for Solubility. Obtain 1 g each of acetanilide, benzoic acid, and naphthalene, and test their solubility with each of the following solvents water, ethyl alcohol or methyl alcohol, and... 

The laboratory plays a crucial role in the detection and characterization of the hemoglobinopathies and thalassemias discussed in the next sections. There have been several recommendations for the laboratory investigation of abnormal Hbs and thalassemias. For example, the 1978 International Committee for Standardization in Hematology expert panel on abnormal Hbs has prepared recommendations for the laboratory investigation of these conditions.In its initial investigation, (1) a complete blood count (CBC), (2) electrophoresis at pH 9.2, (3) tests for solubility and sickling. 

The refined arsenic trioxide is analyzed for purity and also tested for solubility, a term referring to its rate of reactivity with nitric acid this test is important if the arsenic is used in the manufacture of insecticides and herbicides. The product is graded for marketing as white soluble having 99% min As203, white insoluble, or cmde having 95% min As203. 

Solution of Nitrate of Silver, Dissolve 1 drachm crystals of nitrate of. silver in 1 fluid ounce distilled water. It must be protected from tho action of light. Tins is employed os a test for soluble chlorides, any of which, aUghtly acidulated with nitric acid, will give a white, curdy precipitate (chloride of silver) when brought m contact with diluted nitrate of silver. 

List 1. Chemical Classes of Surfactants Tested for Solubility... 

It is interesting to note that the ferrous ion which is essential to the reduction process is hardly present in the products of Eqs. (3) and (7). In this connection, it has been observed that only a faint test for soluble iron can be obtained by spotting on filter paper with sodium sulfide solution... 

Toward the end of the run, the reaction slows down, and it is necessary to introduce steam to carry on and complete the reduction. The test for soluble iron also becomes less distinct. As long as there is any p-nitro- aniline present, a yellow spot test will be obtained on filter paper. p-Phen-ylcnediamine yields a purple spot with a perfectly clear ring around the sludge spot. It is always advisable to test for soluble iron with sodium sulfide to ensure completeness of reduction. If the reduction is not carried on at the boiling temperature, intermediate azo and hydrazo products are sure to be formed. These are not so easily reduced and cause a lowering of the yield. 

Representative tests for the evaluation of immune responses are given in Table 18. The table is not all-inclusive and other tests may be applicable. The examples presented in the table are only representative of the large number of tests that are currently available. The table is informative but incomplete as in the future direct and indirect markers of immune response may be validated and their predictive value documented, thus providing new tests for immunotoxidty. Direct measures of immune system activity by functional assays are the most important types of test for immunotoxicity. Functional assays are generally more important than tests for soluble mediators, which are more important than phenotyping. Signs of illness may be important in in vivo experiments, but symptoms may also have a significant role in studies of immune function in clinical trials and postmarket studies. 

In a typical test for solubility, 40 mg of solute is added to 1 mL of solvent. Therefore, if you were testing the solubility of these three substances, cholesterol would be insoluble, caffeine would be partially soluble, and citric acid would be soluble. Note that a small amount (0.002 mg) of cholesterol would dissolve. It is unlikely, however, that you would be able to observe this small amount dissolving, and you would report that cholesterol is insoluble. On the other hand, 22 mg (55%) of fhe caffeine would dissolve. It is likely that you would be able to observe this, and you would state that caffeine is partially soluble. 

Sodium hydroxide. If the compound is water-insoluble, test its solubility in 1.5 M NaOH solution. Carboxylic acids, which are strong acids, and phenols, which are weak acids, dissolve in sodium hydroxide because they are converted into their water-soluble sodium salts (Eqs. 25.4a and 25.4b). An unknown that is more soluble in NaOH than in water may be either a phenol or a carboxylic acid, and it must be tested for solubility in the weaker base, 0.6 M NaHC03, which may permit distinction between these two functional groups (Part 2, below). If the unknown does not exhibit solubility in NaOH, its solubility in NaHC03 need not be tried rather, it should next be tested for solubility in 1.5 M HCl. 

Preparation of steel substrates before application of paints and related products— Tests for the assessment of surface cleanliness— Part 1 Field test for soluble iron corrosion products... 

Step III Water-insoluble compounds are tested for solubility in a 5% aqueous NaOH solution. If soluble, determine the solubility in 5% aqueous NaHCOs.The use of the NaHCOs solution aids in distinguishing between strong (soluble) and weak (insoluble) acids. 

Step IV Compounds insoluble in 5% aqueous NaOH are tested for solubility in a 5% HQ solution. 

Films were tested for solubility at room temperature in varioius polar solvents. The T values of the polyimides were measured by thermomechanical aSalysis (TM in static air at ID°/min heating rate. Thermo gravimetric analyses (TGA) were performed by means of a Stanton-Redcroft 750 Model under nitrogen at a heating rate of 10°/min. Isothermal gravimetric analyses were carried out at 250 . for 300 hours. 

The qualitative solubilities of polyimlde films cured at 300 are presented in Table 2. The films were tested for solubility at 3% solids in N-methyl pyrrolidone (NMP), N,N-dimethyl acetamide(DMA.c) DMF and hexamethyl phosphoramide (HMPA). Solubilities of polyimides... 

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