Equivalent quantities

With inereasing temperature the two-phase tie-line beeomes shorter and shorter until the two eonjugate phases beeome identieal at a eritieal point where the maximum and minimum in the isothemi have eoaleseed. Thus the eritieal point is defined as that point at whieh 8 p/Sk) and (S />/(3k ) are simultaneously zero, or where the equivalent quantities 8 AldV) ai d 8 AldV ) axe, simultaneously zero. These requirements yield the eritieal eonstants in temis of the eonstants R, a and b. 

If ethyl acetoacetate is warmed with an equivalent quantity of phenyl hydrazine, the corresponding phenylhydrazone (A) is readily formed. On... 

Owing to the comparatively negligible difference in the cost of bromine and the equivalent quantity of constat boiling point hydrobromio acid, there is little to be gained—apart from the instructional value—in preparing the hydrobromio acid from bromine in the preparation of alkyl bromides. 

A condition of equilibrium is reached (70-90 per cent, of bisulphite compound with equivalent quantities of the reagents in 1 hour), but by using a large excess of bisulphite almost complete conversion into the... 

The carbonyl compound may be mixed with an aqueous solution of sodium or potassium cyanide and mineral acid is added, or the bisulphite compound may be treated with an equivalent quantity of sodium cyanide, for example ... 

Add 4 0 g. (4 0 ml.) of pure anihne dropwise to a cold solution of ethyl magnesium bromide (or iodide) prepared from 1 Og. of magnesium, 5 0 g. (3-5 ml.) of ethyl bromide (or the equivalent quantity of ethyl iodide), and 30 ml. of pure, sodium-dried ether. When the vigorous evolution of ethane has ceased, introduce 0 02 mol of the ester in 10 ml. of anhydrous ether, and warm the mixture on a water bath for 10 minutes cool. Add dilute hydrochloric acid to dissolve the magnesium compounds and excess of aniline. Separate the ethereal layer, dry it with anhydrous magnesium sulphate and evaporate the ether. Recrystallise the residual anihde, which is obtained in almost quantitative yield, from dilute alcohol or other suitable solvent. 

Dissolve equivalent quantities of the reagent and of the amine in a small amount of rectified spirit. K no reaction appears to take place in the cold, reflux the mixture for 5-15 minutes. Upon cooling (and scratching with a glass rod, if necessary) the crystaUiiie thiourea separates. RecrystaUise it from rectified spirit or from 60-b0 per cent, alcohol. 

The use of an equivalent quantity of A.R. potassium nitrate is said to produce a more active catalyst. 

Carry out this preparation in the fume cupboard. Dissolve 100 g. of chloroacetic acid (Section 111,125), contained in a large porcelain basin or casserole, in 200 ml. of water. Warm the solution to about 50°, using a 200° thermometer as a stirring rod. Introduce 90 g. of pure, powdered sodium bicarbonate in small quantities at a time with stirring maintain the temperature at 50-60° until effervescence ceases. Now add 80 g. of pure, finely-powdered potassium cyanide (or an equivalent quantity of sodium cyanide), stir the mixture without further warming until the... 

Picrates are usually prepared by mixing solutions of equivalent quantities of the two components in the minimum volume of rectified spirit and allowing to cool the derivative separates in a crystalline condition. It is filtered off, washed with a little ether, and pressed on a porous tUe. If the picrate is stable, it is recrystaUised from alcohol, ethyl acetate or ether. 

The modified procedure involves refluxing the N-substituted phthaUmide in alcohol with an equivalent quantity of hydrazine hydrate, followed by removal of the alcohol and heating the residue with hydrochloric acid on a steam bath the phthalyl hydtazide produced is filtered off, leaving the amine hydrochloride in solution. The Gabriel synthesis has been employed in the preparation of a wide variety of amino compounds, including aliphatic amines and amino acids it provides an unequivocal synthesis of a pure primary amine. 

The monoarylurea may be prepared directly from the amine by heating it in aqueous solution with an equivalent quantity of alkali cyanate and excess of acetic acid, for example ... 

Acetyl chloride is not so satisfactory since an equivalent quantity of the amine hydrochloride is simultaneously produced ... 

Decant the liquid layer into a 2 5 litre flask, and dissolve the sodium derivative of acetylacetone in 1600 ml. of ice water transfer the solution to the flask. Separate the impiue ethyl acetate layer as rapidly as possible extract the aqueous layer with two 200 ml. portions of ether and discard the ethereal extracts. Treat the aqueous layer with ice-cold dilute sulphimic acid (100 g. of concentrated sulphiu-ic acid and 270 g. of crushed ice) until it is just acid to htmus. Extract the diketone from the solution with four 200 ml. portions of ether. Leave the combined ether extracts standing over 40 g. of anhydrous sodium sulphate (or the equivalent quantity of anhydrous magnesium sulphate) for 24 hours in the ice chest. Decant the ether solution into a 1500 ml. round-bottomed flask, shake the desiccant with 100 ml. of sodium-dried ether and add the extract to the ether solution. Distil off the ether on a water bath. Transfer the residue from a Claisen flask with fractionating side arm (Figs. II, 24, 4r-5) collect the fraction boiling between 130° and 139°. Dry this over 5 g. of anhydrous potassium carbonate, remove the desiccant, and redistil from the same flask. Collect the pure acetji-acetone at 134r-136°. The yield is 85 g. 

Acetone in conjunction with benzene as a solvent is widely employed. With cyclohexanone as the hydrogen acceptor, coupled with toluene or xylene as solvent, the use of higher reaction temperatures is possible and consequently the reaction time is considerably reduced furthermore, the excess of cyclohexanone can be easily separated from the reaction product by steam distillation. At least 0 25 mol of alkoxide per mol of alcohol is used however, since an excess of alkoxide has no detrimental effect 1 to 3 mols of aluminium alkoxide is recommended, particularly as water, either present in the reagents or formed during secondary reactions, will remove an equivalent quantity of the reagent. In the oxidation of steroids 50-200 mols of acetone or 10-20 mols of cyclohexanone are generally employed. 

Alternatively, the equivalent quantity of palladium chloride dihydrate may be used. 

When ethyl acetoacetate is warmed with an equivalent quantity of phenyl-hydrazine, the compound (I), which is not a true hydrazone, is first formed this undergoes ring formation (II) with loss of ethyl alcohol upon further heating. The product (II) is N or l-phenyl-3-methyl-5-pyrazolone. 

It will be observed that the reaction involves two equivalents of the amine and produces, in addition to the substituted amide, an equivalent quantity of the amine hydrochloride. Acetic anhydride, on the other hand, converts the amine quantitatively into the acyl derivative, for example ... 

The acid dissociation constant has the same form m Brpnsted-Lowry as m the Arrhenius approach but is expressed m the concentration of H30" rather than The concentration terms [H30" ] and [H" ] are considered equivalent quantities m equilibrium constant expressions... 

Sodium and potassium ions are actively absorbed from the intestine. As a consequence of the electrical potential caused by transport of these ions, an equivalent quantity of Cf is absorbed. The resulting osmotic effect causes absorption of water (56). 

Essentially no waste products are formed ia the USP process if hydriodic acid and either sodium hydroxide or sodium carbonate are used as reactants. Water results from use of the former a mole equivalent quantity of carbon dioxide is produced from the latter reagents. Higher quaUty grades may require some purification steps which may result ia wastes from the treatment. Disposal of these impurities must then be carried out. 

Salinity, S(%e), is defined as the weight ia grams of the dissolved inorganic matter ia 1 kg of seawater after all Br and 1 have been replaced by the equivalent quantity of Cl and HCO3 and ate converted to oxide. In over 97% of the seawater ia the world, the salinity S is between 33%c and... 

Barium nitrite [13465-94-6] Ba(N02)2, crystallines from aqueous solution as barium nitrite monohydrate [7787-38-4], Ba(N02)2 H2O, which has yellowish hexagonal crystals, sp gr 3.173, solubihty 54.8 g Ba(NO2)2/100 g H2O at 0°C, 319 g at 100°C. The monohydrate loses its water of crystallization at 116°C. Anhydrous barium nitrite, sp gr 3.234, melts at 267°C and decomposes at 270 °C into BaO, NO, and N2. Barium nitrite may be prepared by crystallization from a solution of equivalent quantities of barium chloride and sodium nitrite, by thermal decomposition of barium nitrate in an atmosphere of NO, or by treating barium hydroxide or barium carbonate with the gaseous oxidiation products of ammonia. It has been used in diazotization reactions. 

This was first demonstrated ia 1862 by Berthelot and Saint-Gibes (32), who found that when equivalent quantities of ethyl alcohol and acetic acid were abowed to react, the esterification stopped when two-thirds of the acid had reacted. Sinularly, when equal molar proportions of ethyl acetate and water were heated together, hydrolysis of the ester stopped when about one-third of the ester was hydroly2ed. By varyiag the molar ratios of alcohol to acid, yields of ester >66% were obtained by displacement of the equbibrium. The results of these tests were ia accordance with the mass action law shown ia equation 5. 

Ion exchange may be thought of as a reversible reaction involving chemically equivalent quantities. A common example for cation exchange is the familiar water-softening reaction... 

Hardness as calcium carbonate The expression ascribed to the value obtained when the hardness-forming salts are calculated in terms of equivalent quantities of calcium carbonate a convenient method of reducing all salts to a common basic for comparison. 

The alkaloid ean be prepared by blowing steam through narcotine methoehloride previously mixed with the equivalent quantity of sodium hydroxide. The identity of the produet, at first ealled i/i-nareeine, with nareeine was established by Roser, and has been eonfirmed by Addinall and Major. /iomoNareeine, C24H29O8N. SHaO, m.p. 173° (dec.) is similarly made from nareotine ethoehloride. 

Although direct nitration was not possible, 2-amino-4-methylselena-zole can be directly brominated by treatment with bromine in carbon tetrachloride, the hydrogen bromide salt of 2-amino-4-methyl-5-bromoselenazole, mp 180°C (decomp.) is formed. However, all attempts to obtain the free base from this salt failed and led to complete decomposition. In this bromination, an equivalent quantity of bromine must be used excess also leads to complete destruction of the molecule. From the decomposition products an oily compound can be detected similar to bromoacetone. ... 

Faolini and Divizia have succeeded in partially resolving inactive linalol into its optically active isomers hut only to the extent of optical rotations of + 1° 70 and — 1° 60 respectively. Linalol was converted into its acid phthalate, and an alcoholic solution of this compound was treated with the equivalent quantity of strychnine. By fractional crystallisation the laevo-rotatory salt, yielding dextro-rotatory linalol, separates first, leaving the more soluble dextro-rotatory strychnine salt, which yielded laevo-rotatory linalol in the mother liquor. 

Schryver has recommended the use of sodamide for the determination of phenols the hydrogen of the phenolic hydroxyl replaces the sodium with the formation of an equivalent quantity of ammonia,... 

Free N,N -bis-[2-(3, 4 -dihydroxyphenyl)-2-hydroxyethyl]-hexamethylene-diamine can be separated from these salts by the addition of the equivalent quantity of caustic alkali solution. It has a melting point of 162° to 165°C and contains half a mol of water of crystallization. 

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