Normality , of solutions

The calculations needed for corrections and normalization of solution X-ray diffraction data, for calculation of radial distribution functions, for model calculations, and for least-squares refinements (16) can conveniently be done on a personal computer for which integrated program systems are available (17). 

Normal Solutions A normal solution contains 1 g equivalent weight of the solute per L of solution. The normalities of solutions used in volumetric determinations are designated as 1 A, 0.1 A, 0.05 A, etc., in this Codex. 

N = normality of solution (g-equivalents/L) n = number of cells between electrodes E = removal efficiency (fraction)... 

FIGURE 3-1 Plot of equivalent conductivity versus - /normality of solution for an aqueous solution of surfactant of type Na+R. ... 

Per 1000 cc. Solution. Normality of Solutions. Grams per Liter. Acid. Grams. MilUmoIs. (COOH)a. CeHsCH (COOH>2. CeHsCH ... 

Molecular weight Normality of solution Absorption TnaxiniiiTn nm MiUimol Extinction- coefficient... 

It is convenient to describe normalization of solutions of the scalar wave equation in terms of the vector normalization N in Table 11-1, page 230. By repeating the above argument, it follows that... 

For such components, as the composition of the solution approaches that of the pure liquid, the fugacity becomes equal to the mole fraction multiplied by the standard-state fugacity. In this case,the standard-state fugacity for component i is the fugacity of pure liquid i at system temperature T. In many cases all the components in a liquid mixture are condensable and Equation (13) is therefore used for all components in this case, since all components are treated alike, the normalization of activity coefficients is said to follow the symmetric convention. ... 

In a binary liquid solution containing one noncondensable and one condensable component, it is customary to refer to the first as the solute and to the second as the solvent. Equation (13) is used for the normalization of the solvent s activity coefficient but Equation (14) is used for the solute. Since the normalizations for the two components are not the same, they are said to follow the unsymmetric convention. The standard-state fugacity of the solvent is the fugacity of the pure liquid. The standard-state fugacity of the solute is Henry s constant. 

The adsorption of nonelectrolytes at the solid-solution interface may be viewed in terms of two somewhat different physical pictures. In the first, the adsorption is confined to a monolayer next to the surface, with the implication that succeeding layers are virtually normal bulk solution. The picture is similar to that for the chemisorption of gases (see Chapter XVIII) and arises under the assumption that solute-solid interactions decay very rapidly with distance. Unlike the chemisorption of gases, however, the heat of adsorption from solution is usually small it is more comparable with heats of solution than with chemical bond energies. 

Allara D L and Nuzzo R G 1985 Spontaneously organized molecular assemblies. 2. Quantitative infrared spectroscopic determination of equilibrium structures of solution-adsorbed normal-alkanoic acids on an oxidized aluminum surface Langmuir 1 52-66... 

Goodyear G and Stratt R M 1996 The short-time intramoleoular dynamios of solutes in liquids. I. An instantaneous-normal-mode theory for friotion J. Chem. Phys. 105 10050-71... 

METHOD 3 This is not really a method. It is more of an idea Strike and others have been toying with. Eleusis had been supporting the idea that one could make use of the common 48% aq HBr if one employed the technique of dehydration . We remember that the water was competing with the Br in the normal 48% solution. But the literature demonstrates that in conditions such as this, a competing acid can strip away the water (dehydrate) from the beta carbon allowing the Br a second chance to pop in. 

The following factors are the equivalent of 1 mL of normal acid. Where the normality of the solution being used is other than normal, multiply the factors given in the table below by the normality of the solution employed. The equivalents of the esters are based on the results of saponification. 

Molality is used in thermodynamic calculations where a temperature independent unit of concentration is needed. Molarity, formality and normality are based on the volume of solution in which the solute is dissolved. Since density is a temperature dependent property a solution s volume, and thus its molar, formal and normal concentrations, will change as a function of its temperature. By using the solvent s mass in place of its volume, the resulting concentration becomes independent of temperature. 

A solution of 0.10 M S04 - is available. What is the normality of this solution when used in the following reactions ... 

Occlusions, which are a second type of coprecipitated impurity, occur when physically adsorbed interfering ions become trapped within the growing precipitate. Occlusions form in two ways. The most common mechanism occurs when physically adsorbed ions are surrounded by additional precipitate before they can be desorbed or displaced (see Figure 8.4a). In this case the precipitate s mass is always greater than expected. Occlusions also form when rapid precipitation traps a pocket of solution within the growing precipitate (Figure 8.4b). Since the trapped solution contains dissolved solids, the precipitate s mass normally increases. The mass of the precipitate may be less than expected, however, if the occluded material consists primarily of the analyte in a lower-molecular-weight form from that of the precipitate. 

From Example A6.2 we know that after 100 steps of the countercurrent extraction, solute A is normally distributed about tube 90 with a standard deviation of 3. To determine the fraction of solute in tubes 85-99, we use the single-sided normal distribution in Appendix lA to determine the fraction of solute in tubes 0-84 and in tube 100. The fraction of solute A in tube 100 is determined by calculating the deviation z (see Chapter 4)... 

One of the first successful techniques for selectively removing solvent from a solution without losing the dissolved solute was to add the solution dropwise to a moving continuous belt. The drops of solution on the belt were heated sufficiently to evaporate the solvent, and the residual solute on the belt was carried into a normal El (electron ionization) or Cl (chemical ionization) ion source, where it was heated more strongly so that it in turn volatilized and could be ionized. However, the moving-belt system had some mechanical problems and could be temperamental. The more recent, less-mechanical inlets such as electrospray have displaced it. The electrospray inlet should be compared with the atmospheric-pressure chemical ionization (APCI) inlet, which is described in Chapter 9. 

Given W G we have q = —aijn n > 0, and hence, the density q is defined by the normal component of the surface forces at At the end, in Section 2.8.3, we establish the stability of solutions with respect to perturbations in the crack shape. 

Lead styphnate monohydrate is precipitated as the basic salt from a mixture of solutions of magnesium styphnate and lead acetate followed by conversion to the normal form by acidification using dilute nitric acid (97—99). 

The sohd can be contacted with the solvent in a number of different ways but traditionally that part of the solvent retained by the sohd is referred to as the underflow or holdup, whereas the sohd-free solute-laden solvent separated from the sohd after extraction is called the overflow. The holdup of bound hquor plays a vital role in the estimation of separation performance. In practice both static and dynamic holdup are measured in a process study, other parameters of importance being the relationship of holdup to drainage time and percolation rate. The results of such studies permit conclusions to be drawn about the feasibihty of extraction by percolation, the holdup of different bed heights of material prepared for extraction, and the relationship between solute content of the hquor and holdup. If the percolation rate is very low (in the case of oilseeds a minimum percolation rate of 3 x 10 m/s is normally required), extraction by immersion may be more effective. Percolation rate measurements and the methods of utilizing the data have been reported (8,9) these indicate that the effect of solute concentration on holdup plays an important part in determining the solute concentration in the hquor leaving the extractor. 

Pour-Point Depressants. The pour point of alow viscosity paraffinic oil may be lowered by as much as 30—40°C by adding 1.0% or less of polymethacrylates, polymers formed by Eriedel-Crafts condensation of wax with alkylnaphthalene or phenols, or styrene esters (22). As wax crystallizes out of solution from the Hquid oil as it cools below its normal pour point, the additive molecules appear to adsorb on crystal faces so as to prevent growth of an interlocking wax network which would otherwise immobilize the oil. Pour-point depressants become less effective with nonparaffinic and higher viscosity petroleum oils where high viscosity plays a dominant role in immobilizing the oil in a pour-point test. 

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