Salt factor

Standard curve stock solutions are prepared after correcting standard for the salt factor. 

Element mg/100 ml Salt factor salt/element g/1000 liters... 

The difference between total silicon and dissolved inorganic silicate (see Section 10.2.11) is usually equal to the particulate silicon in a sample. As different salt factors are used in the two procedures, the accuracy of the estimation may be affected. A better procedure is recommended by the following difference method. 

Total silicon is determined as described above, but the amount of reactive silicate is obtained from another 25 mL sample after addition of 5 mL of CSS solution. Now the same calibration, salt factors and reagent blanks can be used for both determinations. 

The method has no salt factor. Prepare the calibration curve by using the working standard solutions described above (see 2b in Section 12.5.1.2) and by following the procedure outlined for the analysis of sample. 

The method has no salt factor. Prepare the calibration curve by using the working standard solution described under 2b in Section 12.5.2.2 and by following the procedure outlined for analysis of the sample. However, since the working standard solutions do not contain any magnesium salt, the centrifugation step after the heating process is not necessary. The amount of NaOH solution necessary to establish the reaction pH of about 10.5 should be determined in a pre-treatment e qieriment. 

Most studies of the Kelvin effect have been made with salts—see Refs. 2-4. A complicating factor is that of the electrical double layer presumably present Knapp [3] (see also Ref. 6) gives the equation... 

From an electrochemical viewpoint, stable pit growtli is maintained as long as tire local environment witliin tire pit keeps tire pit under active conditions. Thus, tire effective potential at tire pit base must be less anodic tlian tire passivation potential (U ) of tire metal in tire pit electrolyte. This may require tire presence of voltage-drop (IR-drop) elements. In tliis respect the most important factor appears to be tire fonnation of a salt film at tire pit base. (The salt film fonns because tire solubility limit of e.g. FeCl2 is exceeded in tire vicinity of tire dissolving surface in tlie highly Cl -concentrated electrolyte.)... 

The residue in the flask will contain the sodium (or potassium) salt of the acid together with excess of alkali. Just acidify with dilute sulphuric acid and observe whether a crystalline acid separates if it does, filter, recrystallise and identify (Section 111,85). If no crystaUine solid is obtained, the solution may be just neutralised to phenolphthalein and the solution of the alkali salt used for the preparation of a crystaUine derivative. This wiU confirm, if necessary, the results of hydrolysis by method 1. If the time factor is important, either method 1 or the product of the caustic alkali hydrolysis may be used for the identification of the acid. 

Substituents in pyridinium salt Relative rates Isomer proportions (partial rate factors) i 0 p-ratio... 

As has been noted above, there is no gross change in the mechanism of nitration of PhNH3+ down to 82 % sulphuric acid. The increase in o- andp-substitution at lower acidities has been attributed differential salt effects upon nitration at the individual positions. The two sets of partial rate factors quoted for PhNH3+ in table 9.3 show the effect of the substituent on the Gibbs function of activation at the m- and -positions to be roughly equal for reaction in 98 % sulphuric acid, and about 28 % greater at the -position in 82 % sulphuric acid. ... 

Of course, these schemes indicate only that the overall reactions may be classified as nucleophilic 1,3-substitutions and, in the last case, as electrophilic 1,3-substitut ions. The reactions often proceed only in the presence of catalytic or stoichiometric amounts of transition metal salts, while in their absence 1,1--substitutions or other processes are observed. The 1,1-substitutions are also catalyzed by salts of transition metals, and it is not yet well understood, which factors influence the 1,1 to 1,3-ratio. In a number of 1,3-Substitutions there is... 

Acrylonitrile reacts with the sodium salt of 4.5-dimethvl-A-4-thiazoline-2-thione (73J (R4 = R5 = Me) to yield 3-(2-cyanoethyl)-4.5-dimethyl-A-4-thiazoline-2-thione (74) (R4 = R, = Me) (Scheme 35 (160). Humphlett s studies of this reaction showed that the size of the R4 substituent is a determinant factor for the S versus N ratio (161. 162). If R4 == H, 100% of the N-substituted product (74) is obtained this drops to 50% when R4 = methyl, and only the S-substituted product (75) is obtained when R4 = phenyl. The same trend is observed with various CH2 = CH-X (X = C00CH3. COCH3) reagents (149). The S/N ratio also depends on the electrophilic center for CH2 = CH-X systems thus S-reaction occurs predominantly with acrylonitrile, whereas N-substitution predominates with methvlvinvlketone (149). 

A value for the molecular weight which is low by a factor z + 1 is obtained for salt-free solutions if the experimental results are analyzed as if the polymer were uncharged. 

Salt Effects. The definition of a capacity factor k in hydrophobic interaction chromatography is analogous to the distribution coefficient, in gel permeation chromatography ... 

Health and Safety Factors. Although butynediol is stable, violent reactions can take place in the presence of certain contaminants, particularly at elevated temperatures. In the presence of certain heavy metal salts, such as mercuric chloride, dry butynediol can decompose violently. Heating with strongly alkaline materials should be avoided. 

Certain factors and product precursors are occasionally added to various fermentation media to iacrease product formation rates, the amount of product formed, or the type of product formed. Examples iaclude the addition of cobalt salts ia the vitamin fermentation, and phenylacetic acid and phenoxyacetic acid for the penicillin G (hen ylpenicillin) and penicillin V (phenoxymethylpenicillin) fermentations, respectively. Biotin is often added to the citric acid fermentation to enhance productivity and the addition of P-ionone vastly iacreases beta-carotene fermentation yields. Also, iaducers play an important role ia some enzyme production fermentations, and specific metaboHc inhibitors often block certain enzymatic steps that result in product accumulation. 

When the operating temperature exceeds ca 93°C, the catalytic effects of metals become an important factor in promoting oil oxidation. Inhibitors that reduce this catalytic effect usually react with the surfaces of the metals to form protective coatings (see Metal surface treatments). Typical metal deactivators are the zinc dithiophosphates which also decompose hydroperoxides at temperatures above 93°C. Other metal deactivators include triazole and thiodiazole derivatives. Some copper salts intentionally put into lubricants counteract or reduce the catalytic effect of metals. 

Oxides and hydroxides react with HCl to form a salt and water as in a simple acid—base reaction. However, reactions with low solubiHty or insoluble oxides and hydroxides is complex and the rate is dependent on many factors similar to those for reactions with metals. Oxidizing agents such as H2O2, H2SeO, and V2O3 react with aqueous hydrochloric acid, forming water and chlorine. 

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