Carbon tetrachloride acetonitrile

Most published methods are for analysis of crops and soil residues of the intact acaricides. Extraction has been done by stripping, blender or soxhlet. Extraction solvents have included petroleum ether, benzene, carbon tetrachloride, acetonitrile, diethyl ether, methanol and hexane/acetone. Clean-up steps have em -ployed liquid/liquid partitioning and adsorption on activated charcoal, activated charcoal/Florisil, Florisil, alumina and silica gel. Burke (14) reported that CB is not completely recovered from Florisil. Horn and coworkers (7) found that no clean-up was necessary when analyzing dog urine for CB using a Schecter-Haller procedure. For detection of residues, the colorimetric and UV methods have been replaced by gas chromatographic methods employing microcoulometric or electron capture detectors. 

Theoretical calculations on the /Fdithietane 1,3-dioxide 3 =, sy -dithietane 1,3-dioxide 4 equilibrium in the gas phase at HF/6-31G level show that the anti-isomer 3 is slightly favored (by ca. 0.27 kcal moF1) over the, sy -isomer 4. The antijsyn-ratio is 1.6, with a ry -concentration of 36%. Due to different dipole moments of the anti 3 and syn 4, the solvents of low and medium-high polarity such as carbon tetrachloride, acetonitrile, and dimethyl sulfoxide (DMSO) exert a strong influence on the antisyn interconversion, producing an increase in the ry -concentration <2001BOC57>. 

When ruthenium dioxide or ruthenium trichloride is used to catalyze periodate cleavages, it is likely that Ru04 is first formed (equation 33) and then reacts with the double bond as depicted in equations (31) and (32). Sharpless and coworkers have demonstrated that the best solvent system for this reaction is a mixture of carbon tetrachloride, acetonitrile and water, in a volume ratio of 2 2 3. 

M. Odelius and A. Laaksonen, Molecular Dynamics Simulations of Quadrupolar Relaxation of Xe in Carbon Tetrachloride, Acetonitrile and Methanol, Mol. Phys., 82 (1994), 487-501. 

Wilson [7] demonstrated the effectiveness of this model using data for both binary and ternary systems, one example being the carbon tetrachloride-acetonitrile system. This system shows positive deviations from Raoult s law, as shown from the data for presented in fig. 1.11. Wilson [7] found that the best... 

Using Wilson s parameters for the carbon tetrachloride-acetonitrile system, estimate the Raoult law activity coefficients for each component in a equimolar solution. Then estimate the molar Gibbs energy of mixing. 

Fig. 1.11 Plot of the excess Gibbs energy of mixing for the carbon tetrachloride-acetonitrile system against the mole fraction of acetonitrile at 45°C. The points show the experimental results and the solid curve was calculated using equation (1.10.7) with the parameters given by Wilson [7] (see text).

The following density data are reported for the carbon tetrachloride-acetonitrile system at 25° C. 

Calculate the excess Gibbs energy, entropy, and enthalpy of mixing for the carbon tetrachloride-acetonitrile system discussed in questions 3 and 4. Prepare a plot of these data and compare the results with those obtained in the previous question. 

The stereo-complex was obtained at different compositions of the cosolvent mixtures acetonitrile/carbon tetrachloride, acetonitrile/butyl ehloride and butyl chloride/carbon tetrachloride. The results show a high yield of complex formation in pure solvents and when approaches its solvency maximum a decrease of the yield of stereo-complex was observed, indicating that the interactions are impeded. ... 

Brown, I. Smith, F. Liquid-vapour equilibria V. The system carbon tetrachloride + acetonitrile at 45.deg.C Aris/. J. Chem. 1954,... 

Ru04 has been known as a stoichiometric oxidant that reacts with alcohols and olefins for more than 50 years. While not a catalyst in its own right, RUO4 can be formed in situ from a catalytic amount of RUO2 or RuCls and a stoichiometric equivalent of inorganic oxidants, such as NaOCl or NaI04. A special solvent system consisting of a mixture of carbon tetrachloride, acetonitrile, and water at a 2 3 2 ratio has been shown to prevent the formation of Ru-carboxylate complexes with the oxidized products, which inactivate the catalyst (28). 

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