Benzene density

Figure 2.8 (See color insert following page 414.) Probability densities determined by empirical potential structure refinement from neutron diffraction studies of [CjCiIm][Pp5] containing 33 mol% benzene. Densities are for (a) [PF ]", (b) benzene, and (c) [CjCjIm]+ around a central cation. Surfaces are drawn to encompass the top 25% of ions within 8 A for the anion and benzene and 10 A for the cation. (From Dee-tlefs, M., Hardacre, C., Nieuwenhuyzen, M., Sheppard, O., and Soper, A. K., /. Phys. Chem. B, 109, 1593-1598,2005. With permission.)...

A 10.0 g sample of naphthalene (C10H8) mothballs is added to 50.0 ml of benzene (density = 0.879 g/ml). What will be the boiling point of this solution ... 

Benzoic acid, C6H5COOH, is soluble in benzene, CgHg. What is the molality of a solution in which 3.55 g benzoic acid are dissolved in 75 mL of benzene (Density benzene is 0.866 g/mL at the temperature of the experiment.)... 

A horizontal cylindrical drum is 2.00 m in diameter and 4.00 m long. The drum is slowly filled with benzene (density = 0.879 g/cm ). Derive a formula for W, the weight in newtons of the benzene in the tank, as a function of h, the depth of the liquid in centimeters. 

Methyl ethyl ketone, C4H8O, is a solvent popularly known as MEK that is used to cement plastics. How many grams of MEK must be dissolved in 1.00 X 10 mL of benzene, density 0.879 g/mL, to yield a 0.254 molal solution ... 

Asphaltenes were extracted from West Syberian crude by standard method described in previous work (Balabin Syunyaev, 2008). The value 750 g/mol was chosen as average molecular mass of asphaltenes (Mullins et al., 2007). Adsorption of asphaltenes was studied at concentration 1 g/1 in benzene (density 0,88 g/cm, molar mass 78 g/mol). Four fractions of quartz sand, three fractions of dolomite and two fractions of mica were used as adsorbents. Quartz and dolomite particles are considered to be quasispherical particles. Mica models crumbling rock with plate-like particles. Adsorbents were provided by company "Batolit". Its parameters are shown in Table 2. The particle size distribution was evaluated using optical microscope (OPTITECH SME-F2). 

Figure B3.2.9. A benzene moleeule on a graphite surfaee [90], The geometry and the eharge density (mdieated by the surfaees of eonstant density) have been obtained using the PAW method. (Figure by Professor P E Bldehl.)...

Phosphorus(III) oxide dissolves in several organic solvents, for example benzene, carbon disulphide the molecular weight in these solvents corresponds to the formula P40(, as does the density of the vapour, and the structure is ... 

Now calculate the molecular weight of the substance precisely as described on p. 442. The weight of the solvent employed may be calculated from the following densities methanol, 0 810 rectified spirit, 0-807 acetone, 0 797 ethyl acetate, 0 905 chloroform, 1 504 carbon tetrachloride, 1 582 benzene, 0 880 toluene, 0-871 cyclohexane, 0-724 i, 2-dichloroethane, 1 252. 

The purpose of this eornpuLer project is Lo examine several polynuclear aromatic hydrocarbons and to relate their electron density patterns to their carcinogenic activity. If nucleophilic binding to DN.A is a significant step in blocking the normal transcription process of DN.A, electron density in the hydrocarbon should be positively correlated to its carcinogenic potency. To begin with, we shall rely on clinical evidence that benzene, naphthalene, and phenanthrene... 

The electrostatic potential map of benzene (Figure 11 3c) shows regions of high electron density above and below the plane of the ring which is where we expect the most loosely held electrons (the rr electrons) to be In Chapter 12 we will see how this region of high electron density is responsible for the characteristic chemical reactivity of benzene and its relatives... 

According to the orbital hybridization model benzene has six tt elec Irons which are shared by all six sp hybridized carbons Regions of high TT electron density are located above and below the plane of the ring... 

Let s assume that the solute to be separated is present in an aqueous phase of 1 M HCl and that the organic phase is benzene. Because benzene has the smaller density, it is the upper phase, and 1 M HCl is the lower phase. To begin the countercurrent extraction the aqueous sample containing the solute is placed in tube 0 along with a portion of benzene. As shown in figure A6.1a, initially all the solute is present in phase Lq. After extracting (figure A6.1b), a fraction p of the solute is present in phase Uq, and a fraction q is in phase Lq. This completes step 0 of the countercurrent extraction. Thus far there is no difference between a simple liquid-liquid extraction and a countercurrent extraction. 

For benzene at 25°C this becomes AU = 33,900 - 8.314 (298) = 31,400 J mol". The molar volume of a compound is given by V° = (molecular weight)/ (density). For benzene at 25°C, this becomes V° = 78.0/0.879 = 88.7 cm mol". Tlie cohesive energy density is simply the ratio AUy/V°, but in evaluating this numerically, the question of units arises. By convention, these are usually expressed in calories per cubic centimeter, so we write... 

The aromatic ring has high electron density. As a result of this electron density, toluene behaves as a base, not only in aromatic ring substitution reactions but also in the formation of charge-transfer (tt) complexes and in the formation of complexes with super acids. In this regard, toluene is intermediate in reactivity between benzene and the xylenes, as illustrated in Table 2. 

Commercial chlorination of benzene today is carried out as a three-product process (monochlorobenzene and 0- and -dichlorobenzenes). The most economical operation is achieved with a typical product spHt of about 85% monochlorobenzene and a minimum of 15% dichlorobenzenes. Typically, about two parts of -dichlorobenzene are formed for each part of (9-isomer. It is not economical to eliminate the coproduction of the dichlorobenzenes. To maximize monochlorobenzene production (90% monochlorobenzene and 10% dichlorobenzene), benzene is lightly chlorinated the density of the reaction mixture is monitored to minimize polychlorobenzene production and the unreacted benzene is recycled. 

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