Regnault

Regnault s method Obsolete method for determining gas densities by direct weighing of a known volume of gas under known conditions of temperature and pressure. 

Trichloroethane [71-55-6] methyl chloroform, CH CCl, is a colorless, non-flammable Hquid with a characteristic ethereal odor. It is miscible with other chlorinated solvents and soluble in common organic solvents. The compound was first prepared by Regnault about 1840. 

The effects of the constants in the van der Waals equation become more marked as the pressure is increased above atmospheric. Early measurements by Regnault showed tlrat the PV product for CO2, for example, is considerably less tlran that predicted by Boyle s law... 

The parameter z can be obtained from Regnault s results and these show a value of z of 1.064 for hydrogen, 0.9846 for nitrogen, and 0.2695 for carbon dioxide at room temperature and 100 atmospheres pressure. These values are related to tire conections introduced by van der Waals. 

Brucine, C2aH2e04N2. Brucine was first obtained in 1819 by Pelletier and Caventou from Strychnos Nux-vomica bark, then supposed to be derived from Brucea ferruginea. Its composition was determined by Regnault.i ... 

Regnault and Wiedemann, cf. Haber s Thermodynamics of Technical Gas Reactions, Eng. trans., lect. 6. 

The results of Regnault and of E. Wiedemann (which are not in good agreement) indicate that ... 

The researches of F. Neumann (1831), Regnault (1840), and H. Kopp (1864), indicated that solid elements preserve unchanged their atomic heats when they unite to form solid compounds. Thus, the product molecular weight) X s )ecific heat) = (molecular heat) is composed additively of the atomic heats MC = niaiCi + h2 2c2 + n t s + (9)... 

These values differed from the results of Delaroche and Berard, available at the time, but were afterwards confirmed by the more accurate work of Regnault (Regnault, Mem. de Vlnst. France, 26, 1862). 

In the integration of (2) we must know k as a function of v and T. Now it has been shown that cp, cv are functions of T only, hence k is a function of T alone. We shall now assume, as an experimental fact, that cv is independent of temperature in the case, of permanent gases. This was verified to a close degree of approximation by Regnault (cf. 7). 

Regnault expressed the opinion that the coefficients of expan-... 

Clausius (1850), in considering Regnault s data for the latent heat of steam, introduced a new specific heat, applicable to either phase of a saturated complex of two phases, viz., the amount of heat absorbed in raising the temperature of unit mass of a saturated phase by 1°, the pressure being at the same time varied so as to preserve the substance in a saturated state. In the case of a vapour, this is called the specific heat of saturated vapour (a). 

The mean specific heat of saturated steam at a temperature slightly higher than 100° was found by Regnault to be 0 48. 

Regnault investigated the vapour-pressures of water and benzene, both in the liquid and solid states, and represented his results graphically. He con-. eluded that the curves for the liquid and solid joined at the melting-point, and gave a continuous curve. This was shown theoretically to be incorrect. by Ivirchhoff (1858), who proved, by a method to be described later, that the... 

Regnault (1847) instituted a series of experiments to decide whether the vapour-pressure of the solid form of a substance was the same as, or different from, that of the supercooled liquid at... 

Completely Miscible Liquids (benzene and alcohol) show more complicated relations. The total pressure is usually intermediate between the pressures of the pure liquids, and in many cases less than the sum of these, but greater than that of the most volatile component (Regnault). 

Equation (18) was applied by Margules (1895) to calculate the heats of admixture of water and alcohol from the vapour-pressure data of Regnault the results agreed with the direct determinations of Winkelmann (1873). 

There are two very important generalisations which may be established in connexion with the second type of liquid mixtures investigated by Regnault, e.g., mixtures of ether and water. 

ZnS04. 7H20 = 89-4 (10°) 2Hg = 13 2 (10°). The value for 7H20 (ice) is extrapolated from results of Regnault, Person, and Dewar. Thus ... 

Regnault, B. Martin-Delautre, S. Lejay-Collin, M. Lefevre, M. Grimont, P. A. D. Oligonucleotide probe for the visualization of Escherichia coli Escherichia fergu-sonii cells by in situ hybridization Specificity and potential applications. Res. Microbiol. 2000,151,521-533. 

Registration rights, 25 258-259 Regnault, Victor, 25 628 Regression analysis... 

Ecole Polytechnique, the Institute of Egypt, and the suburban Arcueil estates of Laplace and Berthollet. Like Gay-Lussac, the chemists Louis N. Vauquelin, Michel Eugene Chevreul, and Louis Jacques Thenard admitted well-recommended students to their private chemical laboratories. By the 1830s, Dumas and Victor Regnault were training students in larger numbers as part of the expected chemical curriculum. 84... 

Influenced by his experiences in Regnault s Parisian laboratory of chem-... 

Rabi, Isidor Isaac, 253 Ramsay, William, 175 n.48 Ramus, Petrus, 60 Randall, Merle, 228 Raoult, Francis, 143-145, 146-147 Regnault, Victor, 52, 120 n.65 Remick, Edward, 221 Remsen, Ira, 113-114 Reynolds, Osborne, 177 Rice, Oscar K., 223, 254 Richards, Robert J., 15 Richards, Theodore William, 121 Rideal, Eric, 125... 

A number of procedures have been developed to evaluate A 7 [21-34]. The most widely used, which is discussed in this section, is known as the Regnault-Pfaundler method. 

The results of the calibration and reaction experiments are shown in table 8.1 [142]. In this table, t is the time during which a current of intensity /flows through the calibration resistance, V the measured potential drop across the resistance, and m the mass of sample. The values of ATad for the calibration and reaction experiments were determined from the corresponding temperature-time data, using the Regnault-Pfaundler method with 7], Tf, k, and Tc0 calculated from equations 7.12-7.15 (section 7.1). 

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