Saturated facts

A saturated solution contains the maximum amount of dissolved solute possible at a given temperature. If it has less than this amount, it s called an unsaturated solution. Sometimes, under unusual circumstances, the solvent may actually dissolve more than its maximum amount and become supersaturated. This supersaturated solution is unstable, though, and sooner or later solute will precipitate (form a solid) until the saturation point has been reached. 

If a solution is unsaturated, then the amount of solute that is dissolved may vary over a wide range. A couple of rather nebulous terms describe the relative amount of solute and solvent that you can use  

You can say that the solution is dilute, meaning that, relatively speaking, there s very little solute per given amount of solvent. If you dissolve 0.01 grams of sodium chloride in a liter of water, for example, the solution is dilute. I once asked some students to give me an example of a dilute solution, and one replied A 1 margarita. She was right — a lot of solvent (water) and a very little solute (tequila) are used in her example. 

A solution may be concentrated, containing a large amount of solute per the given amount of solvent. If you dissolve 200 grams of sodium chloride in a liter of water, for example, the solution is concentrated. 

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Liquid chromatography is preceded by a precipitation of the asphaltenes, then the maltenes are subjected to chromatography. Although the separation between saturated hydrocarbons and aromatics presents very few problems, this is not the case with the separation between aromatics and resins. In fact, resins themselves are very aromatic and are distinguished more by their high heteroatom content (this justifies the terms, polar compounds or N, S, 0 compounds , also used to designate resins). 

Alkanes from CH to C4gFlg2 typically appear in crude oil, and represent up to 20% of the oil by volume. The alkanes are largely chemically inert (hence the name paraffins, meaning little affinity), owing to the fact that the carbon bonds are fully saturated and therefore cannot be broken to form new bonds with other atoms. This probably explains why they remain unchanged over long periods of geological time, despite their exposure to elevated temperatures and pressures. 

Boron trioxide is not particularly soluble in water but it slowly dissolves to form both dioxo(HB02)(meta) and trioxo(H3B03) (ortho) boric acids. It is a dimorphous oxide and exists as either a glassy or a crystalline solid. Boron trioxide is an acidic oxide and combines with metal oxides and hydroxides to form borates, some of which have characteristic colours—a fact utilised in analysis as the "borax bead test , cf alumina p. 150. Boric acid. H3BO3. properly called trioxoboric acid, may be prepared by adding excess hydrochloric or sulphuric acid to a hot saturated solution of borax, sodium heptaoxotetraborate, Na2B407, when the only moderately soluble boric acid separates as white flaky crystals on cooling. Boric acid is a very weak monobasic acid it is, in fact, a Lewis acid since its acidity is due to an initial acceptance of a lone pair of electrons from water rather than direct proton donation as in the case of Lowry-Bronsted acids, i.e. 

An alternative method for isolating the n-butyl ether utilises the fact that n-butyl alcohol is soluble in saturated calcium chloride solution whilst n-butyl ether is slightly soluble. Cool the reaction mixture in ice and transfer to a separatory fimnel. Wash cautiously with 100 ml. of 2-5-3N sodium hydroxide solution the washings should be alkaline to litmus. Then wash with 30 ml. of water, followed by 30 ml. of saturated calcium chloride solution. Dry with 2-3 g. of anhydrous calcium chloride, filter and distil. Collect the di-n-butyl ether at 139-142°. The yield is 20 g. 

To isomerize safrole to isosafrole one would like to have pure safrole to start with. This, usually, is not the case. Quasi-pure safrole from sassafras oil is ok. Straight-up sassafras oil is probably ok too, though not recommended. The safrole is then refluxed (boiled under a condenser) in a saturated KOHyethanoI solution for about a day and that s it. The temperature of reflux is about 120-140°C owing to the fact that the ethanol (usually boiling around 65-70°C) is saturated with the halide salt. 

Evidence of a different kind is furnished by the fact that the Gurvitsch rule (p. 113) is often obeyed by systems showing Type I isotherms " the amounts of different adsorptives taken up by a given adsorbent, when expressed as a volume of liquid, agree within a few per cent. The order of agreement is illustrated by the typical examples in Table 4.1 for the adsorption of n-alkanes on ammonium phosphomolybdate, and in Table 4.2 which refers to a variety of adsorptives on a silica gel. It must be admitted, however, that there are cases where considerable deviations from the Gurvitsch mle are found, even though the isotherms are of Type 1. Thus, in Table 4.3 the variation in values of the saturation uptake is far outside... 

The success of the process results from the fact that nowhere inside the furnace is heat extracted from the copper-saturated blast furnace buUion through a soUd surface. The problem of accretion formation (metal buUd-up), which has plagued many other attempts to estabUsh a copper dtossing operation of this type, does not arise. In the cooling launder, lead-rich matte and slag accumulate on the water-cooled plates, but these ate designed so that when they ate lifted from the buUion stream, the dross cracks off and is swept into the furnace via the cooled lead pot. 

The significance of the total sulfur content of kerosene varies greatly with the type of oil and the use to which it is put. Sulfur content is of great importance when the kerosene to be burned produces sulfur oxides, which are of environmental concern. The color of kerosene is of Htde significance but a product darker than usual may have resulted from contamination or aging in fact, a color darker than specified may be considered by some users as unsatisfactory. Kerosene, because of its use as a burning oil, must be free of aromatic and unsaturated hydrocarbons the desirable constituents of kerosene are saturated hydrocarbons. 

Density. The density of saturated water and steam is shown in Figure 2 as a function of temperature on the saturation line. As the temperature approaches the critical point, the densities of the Hquid and vapor phase approach each other. This fact is cmcial to boiler constmction and steam purity because the efficiency of separation of water from steam depends on the density difference. 

At equihbrium with relative humidity below 100%, the moisture ia wood is present primarily ia the cell wads. The moisture content at which the ceU wads would be saturated and the ced cavities empty is caded the fiber saturation poiat. Actuady, such distribution is impossible. Beginning at - 90% relative humidity, some condensation may occur ia smad capidaries. The determination of the fiber saturation poiat is based on the fact that certain properties of wood (eg, strength and volume) change uniformly at first with increasing moisture content and then become iadependent of the moisture content (Fig. 2). The equdibrium moisture content (usuady determined by extrapolation), at which the property becomes constant at 25 to 30% moisture, is represented by the fiber saturation poiat. 

Chemical Composition. Wool wax is a complex mixture of esters of water-soluble alcohols (168) and higher fatty acids (169) with a small proportion (ca 0.5%) of hydrocarbons (170). A substantial effort has been made to identify the various components, but results are compHcated by the fact that different workers use wool waxes from different sources and employ different analytical techniques. Nevertheless, significant progress has been made, and it is possible to give approximate percentages of the various components. The wool-wax acids (Table 9) are predominantiy alkanoic, a-hydroxy, and CO-hydroxy acids. Each group contains normal, iso, and anteiso series of various chain length, and nearly all the acids are saturated. 

The earliest study describing vulcanised polymers of esters of acryUc acid was carried out in Germany by Rohm (2) before World War I. The first commercial acryUc elastomers were produced in the United States in the 1940s (3—5). They were homopolymers and copolymers of ethyl acrylate and other alkyl acrylates, with a preference for poly(ethyl acrylate) [9003-32-17, due to its superior balance of properties. The main drawback of these products was the vulcanisation. The fully saturated chemical stmcture of the polymeric backbone in fact is inactive toward the classical accelerators and curing systems. As a consequence they requited the use of aggressive and not versatile compounds such as strong bases, eg, sodium metasiUcate pentahydrate. To overcome this limitation, monomers containing a reactive moiety were incorporated in the polymer backbone by copolymerisation with the usual alkyl acrylates. 

Even though the basic idea of the Widom model is certainly very appealing, the fact that it ignores the possibihty that oil/water interfaces are not saturated with amphiphiles is a disadvantage in some respect. The influence of the amphiphiles on interfacial properties cannot be studied in principle in particular, the reduction of the interfacial tension cannot be calculated. In a sense, the Widom model is not only the first microscopic lattice model, but also the first random interface model configurations are described entirely by the conformations of their amphiphilic sheets. 

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