Neutralisation number

Neutralisation number, 0.15 max Neutralisation number, 0.16 max Neutralization number, 1.0 max Neutralisation number, 1.0 max Neutralisation number, 0.1 max Neutralization number, 3.0 max Steam emulsion number, demnl sibility, and Sligh oxidation number also speoified Dielectric strength, 1-in. disk, 0.1-hi. gap, 25,000 volts Insotable per cent, 0.1 Insoluble per cent, 0.1 Colorless... 

In practice, for fluids of viscosities below 1000 centistokes, the equilibration reaction will take a number of hours at 100-150°C. Residual esters and siliconates which may occur during the reaction are hydrolysed by addition of water and the oil is separated from the aqueous acid layer and neutralised as before. 

Neutralisations-wirme, /. heat of neutralization. -zahl,/. neutralization number, neutralisleren, v.t. neutralize. 

A measuie of the total of a phosphating solution, as indicated by the number of ml of 0 1 n sodium hydroxide (4-0 g/1) needed to neutralise 10 ml of the phosphating solution to phenolphihalein. t Presumably from nitrides present in the steel. 

A large number of substances, called neutralisation or acid-base indicators, change colour according to the hydrogen-ion concentration of the solution. The... 

The theory of titrations between weak acids and strong bases is dealt with in Section 10.13, and is usually applicable to both monoprotic and polyprotic acids (Section 10.16). But for determinations carried out in aqueous solutions it is not normally possible to differentiate easily between the end points for the individual carboxylic acid groups in diprotic acids, such as succinic acid, as the dissociation constants are too close together. In these cases the end points for titrations with sodium hydroxide correspond to neutralisation of all the acidic groups. As some organic acids can be obtained in very high states of purity, sufficiently sharp end points can be obtained to justify their use as standards, e.g. benzoic acid and succinic acid (Section 10.28). The titration procedure described in this section can be used to determine the relative molecular mass (R.M.M.) of a pure carboxylic acid (if the number of acidic groups is known) or the purity of an acid of known R.M.M. 

Discussion. For oils and fats, which are esters of long-chain fatty acids, the saponification value (or number) is defined as the number of milligrams of potassium hydroxide which will neutralise the free fatty acids obtained from the hydrolysis of 1 g of the oil or fat. This means that the saponification number is inversely proportional to the relative molecular masses of the fatty acids obtained from the esters. A typical reaction from the hydrolysis of a glyceride is ... 

The suitability of the ELISA for soil analysis was initially tested by assaying a number of control soil samples, fortified after extraction and neutralisation with Paraquat in the range 10-300mg kgy1. The results in Table 9.19 were close to the expected values and thus confirmed that natural soil components did not interfere with the determination. These results justified the further refinement of the method for soil analysis. 

The formation of rings by this back-biting mechanism implies that when the reaction mixture is neutralised, there should be a number of linear fragments corresponding to the number of catalyst molecules. Careful examination of the reaction mixtures has shown that if such linear fragments are present, their concentration is very much lower than that of the initiator [13] This, therefore, appears to exclude this and any other kind of ring formation by back-biting this question will be discussed in more detail later. 

D Number of moles of hydrochloric acid needed for neutralisation... 

It should be noted that the discussion so far has assumed that all compounds are stoichiometric, i.e. that all the atomic or molecular proportions are integral. It has become increasingly clear that many compounds are to some degree non-stoichiometric. These rules fail for non-stoichiometric compounds, for which further formalisms need to be developed. Electroneutrality must, of course, be maintained overall in such compounds, in one way or another. For example, in an ionic compound where there is apparently a deficit of negative ions, the consequent formal excess of cations may be neutralised by the presence of an appropriate number of cations of the form rather than of the prevalent form Various... 

Acid values are also determined for fixed oils. The acid value for a substance is the number of mg of KOH required to neutralise 1 g of the test substance when it is... 

Analysis of antioxidant properties relative to the DPPH" radical involves observation of colour disappearance in the radical solution in the presence of the solution under analysis which contains antioxidants. A solution of extract under analysis is introduced to the environment containing the DPPH radical at a specific concentration. A methanol solution of the DPPH radical is purple, while a reaction with antioxidants turns its colour into yellow. Colorimetric comparison of the absorbance of the radical solution and a solution containing an analysed sample enables one to make calculations and to express activity as the percent of inhibition (IP) or the number of moles of a radical that can be neutralised by a specific amount of the analysed substance (mmol/g). In another approach, a range of assays are conducted with different concentrations of the analysed substance to determine its amount which inactivates half of the radical in the test solution (ECso). The duration of such a test depends on the reaction rate and observations are carried out until the absorbance of the test solution does not change [4]. If the solution contains substances whose absorbance disturbs the measurement, the concentration of DPPH radical is measured directly with the use of electron paramagnetic resonance (EPR) spectroscopy. 

The meaning of this table is the following if a substance is taken from one of the two columns, say potash from the first, to which corresponds the number 1605, the numbers in the other column indicate the quantity of each acid necessary to neutralise 1605 parts of potash. If a substance is taken from the second column, the numbers in the first column show how much of each of the substances in this column will be necessary for its neutralisation. ... 

Because atmospheric humidity must be avoided, the reaction flask is isolated from the atmosphere with drying tubes. Moreover, since the solvent is rarely perfectly anhydrous and will contain traces of water due to its hygroscopic nature, its water content must be measured prior to the determination. The equivalence point of the titration reaction is detected by an electrical method instead of a visual method. The current intensity that passes between two platinum electrodes inserted in the reaction medium is measured (see Fig. 19.10). The reagent, which is a mixture of sulphur dioxide, iodine and a base, is characterised by the number of mg of water that can be neutralised by 1 cm3 of this reagent. This is referred to as the equivalent mass concentration of water, or the titre T of the reagent. 

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