Free water, definition

By definition, the anion-free water is free of salt. When pressure is applied to a clay-brine slurry to force out water (as that described in the experimental section), the solution that flows out of the cell should maintain the same chloride concentration as the brine s if the anion-free water is immobile. Otherwise, the concentration of the chloride decreases. Pressure forces water to flow through the pores with a certain velocity meanwhile, the pore size... 

Application of ion exchange refining to the process for the manufacture of dextrose may be understood from the following description of such a process. Triple-washed starch is diluted with ion-free water to the desired concentration and is acidified with a definite quantity of mineral acid such as hydrochloric or sulfuric. It is desirable that the acidified starch slurry be held for at least thirty minutes in order to permit an effective equilibrium acidity to be reached. The starch slurry may contain a quantity of soft water salts which consume acid, and since this consumption is variable, the acidity is checked and adjusted to the desired level following the holding period. The conversion is then carried out at elevated temperature and under pressure for a period sufficient to yield maximum dextrose. The conversion may be carried out batchwise in an autoclave, or continuously. 

Free-Water Knockout. By definition, free water is any water associated with the crude-oil emulsion that settles out within 5 min while the produced fluids are stationary in a settling space within a vessel. Free-water knockouts (FWKO) are simply three-phase separation vessels that separate... 

Recently, Steinbach and Sucker (23) reported about the formation of l+-H20-molecule structures that may develop on the hydrophilic groups of surface active compounds upon dilatation of a l-H20-molecu-le structure, by adsorbing 3-water molecules from the subphase at a water-air interface. In the case of the water-oil interphase of the microemulsion, the dispersed droplet consits of an interphasal choro-na that surrounds an inner water core the free water fraction of the latter (bulk-H20)is the subphase that, acting as a reservoir, supplies H2O molecules to the interphase region. Since the formation of hydrated structures takes place at ons ant sur ace tension (23), the above mechanism allows the water-oil interface to expand without affecting the surface pressure necessary to maintain the system s equilibrium. In this way while the area of every polar head of the amphi-phile remains constant, the interphase area stabilized by a single polar head increases up to the amount corresponding to the definite area requirement of the it-H20-molecule structure (23) (3-6). 

Figure 2 shows typical drying curves for commercial p-hemihydrate that was preconditioned in three different environments to prepare samples with different amounts of free moisture. The curves exhibit a definite plateau after only a few minutes of exposure to microwaves, which is a strong indication that the weight loss is due to free water removal only. 

Adopting the more realistic definition of the internal water activity as being the ratio of the number of moles of free water... 

Odor threshold The greatest dilntion of a sample with odor-free water to yield the least definitely perceptible odor. 

Furthermore, the broad definition which defines mineral matter as all elements in coal except carbon, hydrogen, nitrogen, oxygen, and sulfur needs some modification since four of these five elements occur in inorganic locations and are, therefore, part of the mineral matter. For example, (1) carbon occurs in carbonates (2) hydrogen occurs in water of hydration, as well as in any free water in the coal (3) oxygen occurs in carbonates, sulfates, and silicates as well as in water as well as in water of hydration and free water in the coal and (4) sulfur occurs in sulfates and sulfides, predominantly pyrite and marcasite. 

The situation is far more complicated for non-spherical or more complex solvent molecules. In the first place, the very concept of a hard-core diameter is not a well-defined quantity. For water, for instance, one may conveniently choose the effective diameter of the water molecule as the location of the first peak of the radial distribution function g R) for pure water. If we adopt this definition, we find that there exists a small positive temperature dependence of the molecular diameter of water. The rationale for this behavior is quite simple. In liquid water at room temperature, most of the water molecules are engaged in hydrogen bonds. The optimal distance for a hydrogen bond is about 2.76 A, well within the effective hard-core diameter assigned to a water molecule, about 2.8 A. As the temperature increases, one should consider at least two competing effects. On the one hand, we have the kinetic energy effect that was described above, which tends to decrease the effective diameters of the free water molecules. On the other hand, hydrogen-bonded pairs are broken as we increase the temperature hence. 

Taste and odor No health-based guideline value. The threshold odor number (TON) is the greatest dilution of sample with odor-free water yielding definitely perceptible odor SC No value set 3TCN Flavor profile analysis... 

At the point where such gets solidify, they still contain much water, but because the pores are so small the vapor pressure is far less than that of free water. As described in a previous section, these hydrated silicas sometimes appear to give up water stepwise, as though definite hydrates were present. 

Discussion. The hydroxides of sodium, potassium, and barium are generally employed for the preparation of solutions of standard alkalis they are water-soluble strong bases. Solutions made from aqueous ammonia are undesirable, because they tend to lose ammonia, especially if the concentration exceeds 0.5M moreover, it is a weak base, and difficulties arise in titrations with weak acids (compare Section 10.15). Sodium hydroxide is most commonly used because of its cheapness. None of these solid hydroxides can be obtained pure, so that a standard solution cannot be prepared by dissolving a known weight in a definite volume of water. Both sodium hydroxide and potassium hydroxide are extremely hygroscopic a certain amount of alkali carbonate and water are always present. Exact results cannot be obtained in the presence of carbonate with some indicators, and it is therefore necessary to discuss methods for the preparation of carbonate-free alkali solutions. For many purposes sodium hydroxide (which contains 1-2 per cent of sodium carbonate) is sufficiently pure. 

The ability of polyvalent cations leached from the glass to suppress the free-fluoride ion concentration in basalt ground water is difficult to assess. Fluoride definitely enhances leaching and is the primary cause of the high concentrations of dissolved plutonium in the basalt ground-water leachate. Once the plutonium is dissolved, however, it is not possible to determine what fraction is stabilized by fluoride as opposed to other species leached from the glass. 

---