From water

The utility system also creates waste through products of combustion from boilers and furnaces and wastewater from water treatment, boiler blowdown, etc. Utility waste minimization is in general terms a question of ... 

Crystallizes from water in large colourless prisms containing 2H2O. It is poisonous, causing paralysis of the nervous system m.p. 101 C (hydrate), 189°C (anhydrous), sublimes 157°C. It occurs as the free acid in beet leaves, and as potassium hydrogen oxalate in wood sorrel and rhubarb. Commercially, oxalic acid is made from sodium methanoate. This is obtained from anhydrous NaOH with CO at 150-200°C and 7-10 atm. At lower pressure sodium oxalate formed from the sodium salt the acid is readily liberated by sulphuric acid. Oxalic acid is also obtained as a by-product in the manufacture of citric acid and by the oxidation of carbohydrates with nitric acid in presence of V2O5. 

TbF4 (TbF, -f F, at 3(WC) and Cs,Tbp7 are known and Tb oxides intermediate between Tb, , and TbO, are formed by healing Tb compounds in air. These higher oxides liberate oxygen from water. Tb, , and TbCl (TbCl, plus Tb) have metal-metal bonding. 

Surface heterogeneity may be inferred from emission studies such as those studies by de Schrijver and co-workers on P and on R adsorbed on clay minerals [197,198]. In the case of adsorbed pyrene and its derivatives, there is considerable evidence for surface mobility (on clays, metal oxides, sulfides), as from the work of Thomas [199], de Mayo and co-workers [200], Singer [201] and Stahlberg et al. [202]. There has also been evidence for ground-state bimolecular association of adsorbed pyrene [66,203]. The sensitivity of pyrene to the polarity of its environment allows its use as a probe of surface polarity [204,205]. Pyrene or ofter emitters may be used as probes to study the structure of an adsorbate film, as in the case of Triton X-100 on silica [206], sodium dodecyl sulfate at the alumina surface [207] and hexadecyltrimethylammonium chloride adsorbed onto silver electrodes from water and dimethylformamide [208]. In all cases progressive structural changes were concluded to occur with increasing surfactant adsorption. 

The other peaks demonstrate the power of NMR to identify and quantitate all the components of a sample. This is very important for die phannaceutical industry. Most of the peaks, including a small one accidentally underlying the methyl resonance of paracetamol, arise from stearic acid, which is connnonly added to paracetamol tablets to aid absorption. The integrals show diat it is present in a molar proportion of about 2%. The broader peak at 3.4 ppm is from water, present because no attempt was made to dry the sample. Such peaks may be identified either by adding fiirther amounts of the suspected substance, or by the more fiindamental methods to be outlined below. If the sample were less concentrated, then it would also be... 

Half-reaction (i) means that Co(II) in aqueous solution cannot be oxidised to Co(III) by adding ammonia to obtain the complexes in (ii), oxidation is readily achieved by, for example, air. Similarly, by adding cyanide, the hexacyanocobaltate(II) complex becomes a sufficiently strong reducing agent to produce hydrogen from water ... 

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. 

Iron(III) chloride forms numerous addition compounds, especially with organic molecules which contain donor atoms, for example ethers, alcohols, aldehydes, ketones and amines. Anhydrous iron(III) chloride is soluble in, for example, ether, and can be extracted into this solvent from water the extraction is more effective in presence of chloride ion. Of other iron(III) halides, iron(III) bromide and iron(III) iodide decompose rather readily into the +2 halide and halogen. 

Hydrated cobalt III) sulphate, Co2(S04)3. JSHjO is obtained when cobalt(II) sulphate is oxidised electrolytically in moderately concentrated sulphuric acid solution it is stable when dry but liberates oxygen from water. Some alums, for example KCo(S04)2.12H,0 can be obtained by crystallisation from sulphuric acid solutions. In these and the sulphate, the cation [CofHjO) ] may exist it is both acidic and strongly oxidising. 

Pure ethyl hydrogen sulphate is difficult to prepare, as it is an oily liquid, very soluble in water, and easily hydrolysed. It is therefore usually isolated as the potassium salt, since potassium ethyl sulphate crystallises well from water, and is not readily hydrolysed in neutral or weakly alkaline solution. 

Pure Ether. Pure ether (entirely free in particular from water) is frequently required in the laboratory, and especially for the preparation and use of Grignard reagents. It is best prepared in quantity for classes by adding an ample quantity of granular calcium chloride to a Winchester bottle of technical ether, and allowing the mixture to stand for at least 24 hours, preferably with occasional shaking. The greater part of the water and... 

Succinamide. NHoCOCH2 CH2CONH2. (Method 2(a)). Add 5 ml. (5 8 g.) of dimethyl succinate to a mixture of 50 ml. of water and 25 ml. of concentrated [dy o-88o) aqueous ammonia solution in a 150 ml. conical flask. Cork the flask and shake the contents the dimethyl succinate rapidly dissolves to give a clear solution. Allow the solution to stand after about i hour the succinamide starts to crystallise, and then continues to separate for some time. Next day, filter off the succinamide at the pump, wash with cold water, and drain. Recrystallise from water, from which the succinamide separates as colourless crystals the latter soften at 240° and melt at 254 -255° with... 

The camphorquinone can be purified in either of two ways, (i) To save time, the drained but still damp material can be recrystallised from water containing 10% of acetic acid, the hot filtered solution being cooled and vigorously stirred. The quinone separates as brilliant yellow crystals (yield, 2 5 g.), m.p. 192-194 , increased to 196-197 by a second reciystal-lisation. (ii) The crude camphorquinone can be dried in a vacuum desiccator (weight of dry quinone, 5 g.), and then recrystallised from petroleum (b.p. 100-120 ), the hot solution being filtered through a fluted paper in a pre-heated funnel. The quinone separates in beautiful crystals, m.p. 196-197 , 2 8 g. 

If desired, the 3,5-dinitrobenzoic acid may be re crystallised from water as almost colourless rhombs, m.p. 204 . 

Add 4 g. of malonic acid to 4 ml. of pyridine, and then add 3 1 ml. of crotonaldehyde. Boil the mixture gently under reflux over an asbestos-covered gauze, using a small Bunsen flame, for 40 minutes and then cool it in ice-water. Meanwhile add 2 ml. of concentrated sulphuric acid carefully with shaking to 4 ml. of water, cool the diluted acid, and add it with shaking to the chilled reaction-mixture. Sorbic acid readily crystallises from the solution. Filter the sorbic acid at the pump, wash it with a small quantity of cold water and then recrystallise it from water (ca, 25 ml.). The colourless crystals, m.p. 132-133°, weigh ro-i-2 g. 

I. Oxidation to benzoic acid. Boil a mixture of i ml. of benzyl chloride, 50 ml. of saturated aqueous KMn04 solution and 2 g. of anhydrous Na.jCOj under reflux for 30 minutes. Acidify with cone. HCl and then add 25% Na SOj solution until the brown precipitate of MnOj has dissolved. On cooling, benzoic acid crystallises out. Filter through a small Buchner funnel, wash with water and identify (P 347) When recrystallised from water, benzoic acid has m.p. 121 . 

Silver nitrite. Warm concentrated solutions of silver nitrate (containing 48 g. of AgNOj) and potassium nitrite (containing 30 g. of KNOj) are mixed, and the mixture is allowed to cool. The silver nitrite which separates is filtered off and washed with water. It may be recrystallised from water at 70°, and is dried either in a vacuum desiccator or in an air oven at about 40° the yield is about 90 per cent. Silver nitrite should be stored in an tightly-stoppered amber bottle. 

Optional or alternative experiments are the recrystaUisation of 3-0 g. of crude benzoic or salicylic acid from water. 

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