Berthelot

For making slight correction for nonideality in dilute gases, Berthelot changed the equation to  

Equation (2) is given in Ref 8, p 161, where it is stated that Berthelot equation is derived from Clausius equation (See item 

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The parameters in simple potential models for interactions between unlike molecules A and B are often deduced from tlie corresponding parameters for the A-A and B-B interactions using combination mles . For example, the a and e parameters are often estimated from the Lorentz-Berthelot mles ... 

Acetylene was discovered m 1836 by Edmund Davy and characterized by the French chemist P E M Berthelot m 1862 It did not command much attention until its large scale preparation from calcium carbide m the last decade of the nineteenth century stim ulated interest m industrial applications In the first stage of that synthesis limestone and coke a material rich m elemental carbon obtained from coal are heated m an electric furnace to form calcium carbide... 

Berthelot s equation of state, used by many thermodynamicists, is... 

It is, however, possible to calculate the tensile strength of a liquid by extrapolation of an equation of state for the fluid into the metastable region of negative pressure. Burgess and Everett in their comprehensive test of the tensile strength hypothesis, plot the theoretical curves of T /T against zjp, calculated from the equations of state of van der Waals, Guggenheim, and Berthelot (Fig. 3.24) (7], and are the critical temperature and critical... 

Fig. 3.24 Test of the tensile strength hysteresis of hysteresis (Everett and Burgess ). TjT, is plotted against — Tq/Po where is the critical temperature and p.. the critical pressure, of the bulk adsorptive Tq is the tensile strength calculated from the lower closure point of the hysteresis loop. C), benzene O. xenon , 2-2 dimethyl benzene . nitrogen , 2,2,4-trimethylpentane , carbon dioxide 4 n-hexane. The lowest line was calculated from the van der Waals equation, the middle line from the van der Waals equation as modified by Guggenheim, and the upper line from the Berthelot equation. (Courtesy Everett.)...

Berthelot) reagent Berthierine [12178-37-9] Bertholet s silver Bertrandite [12161-82-9] Beryl... 

Formic acid [64-18-6] (methanoic acid) is the first member of the homologous series of alkyl carboxyHc acids. It occurs naturally ia the defensive secretions of a number of insects, particularly of ants. Although the acid nature of the vapors above ants nests had been known since at least 1488, the pure acid was not isolated until 1671, when the British chemist John Ray described the isolation of the pure acid by distillation of ants (1). This remained the main preparative method for more than a century until a convenient laboratory method was discovered by Gay-Lussac (2). The preparation of formates using carbon monoxide was described by Berthelot in 1856. 

Reaction with 1,3-benzenediamine-periodate (91) or with a hypochlorite—alkaline phenol (Berthelot) reagent enables the detection of both 2- and 4-aminophenol, the latter reagent giving distinguishable blue and dark green products, respectively (92). 4-Aminophenol itself has been shown to react in alkaline solution with both the 2- and 3-aminophenol isomers, a reaction exploited for their detection (93). 

Kinetic Considerations. Extensive kinetic and mechanistic studies have been made on the esterification of carboxyHc acids since Berthelot and Saint-GiHes first studied the esterification of acetic acid (18). Although ester hydrolysis is catalyzed by both hydrogen and hydroxide ions (19,20), a base-catalyzed esterification is not known. A number of mechanisms for acid- and base-catalyzed esterification have been proposed (4). One possible mechanism for the bimolecular acid-catalyzed ester hydrolysis and esterification is shown in equation 2 (6). 

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. 

A new kinetic enzymatic method for the routine determination of urea in semm has been evaluated. This method is based upon an enzymatic reaction and formation of a coloured complex. The method is based on a modified Berthelot reaction. The reaction was monitored specRophotomebically at 700 nm (t = 25 0.1 °C). The optimal pH value, chosen for the investigation of complex, is 7.8. 

B. Ozonizer. The conversion of oxygen to ozone is accomplished by means of three Berthelot tubes constructed of soft lime glass (Note 2) with the dimensions shown in Fig. 3. It is important that the glass be thoroughly cleaned and that the... 

The three Berthelot tubes are mounted vertically in a large battery jar about 13 in. by 9 in. by 18 in. (Note 5). They are held in place by a wooden top (see Fig. 4) which has holes and slots cut to fit the tubes. A second wooden block with holes and slots to fit the bottom of the Berthelot tubes (Fig. 3) is placed in the bottom of the battery jar. It should be weighted with a few pieces of lead. Both the top and the bottom blocks should be soaked in hot molten paraffin wax. The holes in the top should... 

Berthelot tubes constructed of Pyrex either fail to produce ozone or give a low yield. However, Henne and Perilstein have recently described a satisfactory ozonizer constructed of Pyrex glass. 

It is necessary to cool the water inside the Berthelot tubes since the temperature of the small volume of water in the inner tube reaches 40° or higher a short time after the current is turned on, with consequent reduction in the amount of ozone produced. It is usually not necessary to cool the large volume of water in the battery jar. 

In 1869 Berthelot- reported the production of styrene by dehydrogenation of ethylbenzene. This method is the basis of present day commercial methods. Over the year many other methods were developed, such as the decarboxylation of acids, dehydration of alcohols, pyrolysis of acetylene, pyrolysis of hydrocarbons and the chlorination and dehydrogenation of ethylbenzene." ... 

Good-GLrifalco-Fowkes (GGF) equation Using ysi = ysv + yiv - 20(ysvyiv) in Young s equation leads to 1+COS0 2 Uvj Yggf obtained from a plot COS0 versus 4> is solid-liquid interaction parameter 0 = 1 if the interactions are purely dispersive. Based on Berthelot relation for attractive constants valid only when the solid-liquid interactions are dominantly dispersive. [77-82]... 

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