Benzene refractive index

This device has been manufactured by GOW-MAC Inc., who claimed it had a sensitivity of 1 x 10 refractive index units. This would be equivalent to a sensitivity of 9 x 10 g/ml of benzene (refractive index 1.501) eluted in w-heptane (refractive index 1.388). The cell volume was kept to 8 pi, a little large for modern sensors but small enough to work well with normal 4.6 mm I.D. columns. Different cells packed with appropriate materials were necessary to cover the refractive index range of 1.31 to 1.60. A diagram of the Christiansen detector is shown in figure 5. 

To a solution of 93.8 g of the monoglycol ester in 500 ml of benzene, there are added 55 g of nicotinic acid chloride and 25 g of trimethylemine dissolved in 200 ml of benzene. The solution is stirred gently at a temperature of 60°C for two hours. After this time, the solution is cooled and washed successively with water, dilute hydrochloric acid, dilute ammonia and water until neutrality, it is dried over anhydrous sodium sulfate, and the sol vent Is evaporated under vacuum In this wey llOg of glycol 2-(p-chlorophenoxy)-2-methylpropionate nico-tlnate Is prepared, which represents a yield of 84%. The product is a sllghly yellow oil having a refraction index of no = 1.5422 and which is distilled with decomposition et 214°C at a pressure of 0.3 mm. 

One can read letters through the porous PVA-PVAc film in benzene, but one cannot do so in cyclohexane nor in the case of the blank. This is supported by the fact that the refractive indices of benzene are close to that of PVA, but the refractive index of cyclohexane is far from that of PVA. When the porous film was dipped in a mixed solvent of benzene and cyclohexane (8.0 2.0 in weight), it became semi-transparent. To make this point clearer, the refractive index and the dispersive power of polymers and organic solvents were measured. The results are shown in Table 3, which shows that the refractive index of PVA is near that of benzene and that the dispersion power of aliphatic compounds is lower than that of aromatic compounds. 

Table 5 Influence of Refractive Index on Color of Porous Film (Expt. No. 3) in Mixed Solvents of Benzene and Bromobenzene...

Solvent — The transition energy responsible for the main absorption band is dependent on the refractive index of the solvent, the transition energy being lower as the refractive index of the solvent increases. In other words, the values are similar in petroleum ether, hexane, and diethyl ether and much higher in benzene, toluene, and chlorinated solvents. Therefore, for comparison of the UV-Vis spectrum features, the same solvent should be used to obtain all carotenoid data. In addition, because of this solvent effect, special care should be taken when information about a chromophore is taken from a UV-Vis spectrum measured online by a PDA detector during HPLC analysis. 

GPC analyses were performed with a Waters Model 244 chromatograph using Microstyragel columns. Both differential refractive index and UV (254 nm) detectors were used. THF was the eluant with a flow rate of 2 ml min-1. A benzene internal standard was employed to correct for flow variations and for normalization of the integrated peak areas. The column set was calibrated using nearly monodispersed polystyrene standards and all molecular data are reported as polystyrene-equivalent molecular weights. 

The error in (a) is stated to compare favourably with calibration from benzene, since the absolute value of R90 is hardly known to this accuracy. In (b) the concentration of DNA was measured spectrophotometrically via the molar phosphorous extinction coefficient of 6415 (with a standard deviation of 2%). The low error in (c) arises from low levels of dust achieved as well as the integration over a period of 10 secs of the readings on a digital output. The specific refractive index increment used in (d) was an experimental one from the literature. In point of fact the assess-... 

The product obtained from the high-pressure reaction of benzene has been identified as amorphous [309]. The amorphous character of the sample prevents the obtainment of the Raman spectra. Other physical-chemical properties of the reaction product are the following refractive index n = 1.75 density p = 1.39 g/cm elastic constant Bq = 80 GPa optical gap 2.5 eV. These values must to be considered only as typical values of the properties because, as described above, the reaction product is reported to change according to the... 

Ratz et al. reported on the synthesis of this cyclophosphazene in which the chlorine atoms of NjPjClg are substituted by 2- methyl aziridine (propyleneimine) groups in the presence of H3N or Et3N in benzene. However, the original paper provides only very few characteristics of the sample in question, i.e., elemental analysis and refractive index, n = 1.5071. 

When acetic acid is diffusing from a 1.9 iV solution in water into benzene, spontaneous emulsion forms on the aqueous side of the interface, accompanied by a little interfacial turbulence. Results can be obtained with this system, however, if in analysing the refractive index gradient near the surface a correction is made for the spontaneous emulsion the rate of transfer is then in excellent agreement (57) with Eq. (20) (Fig. 6). Consequently there is no appreciable energy barrier due to re-solvation of the acetic acid molecules at the interface, nor does the spontaneous emulsion affect the transfer. With a monolayer of sodium lauryl... 

White tetragonal or orthorhombic crystal density 1.17g/cm3 refractive index 1.74 unstable, sublimes readily at ordinary temperatures vapor pressure 748 torr at 32°C highly soluble in water, alcohol, liquid ammonia and liquid hydrogen sulfide insoluble in benzene, hexane and ether. 

Colorless liquid commercial grade has a pungent disagreeable odor, in its purest form the odor is sweet and pleasant flammable refractive index 1.6295 density 1.261 g/mL at 20°C boils at 46.3°C freezes at -110.8°C critical temperature 279°C, critical pressure 77.97 atm, critical volume 173 cm3/mol slightly soluble in water, 0.29 g/lOOg at 20°C soluble in alcohol, ether, benzene, chloroform, and oils forms an azeotrope with water (CS2 H2O = 97.2%)... 

Colorless noncombustible liquid chloroform-like odor refractive index 1.4601 density 1.5867g/mL at 20°C boils at 76.8°C freezes at -23°C critical temperature 283.5°C, critical pressure 44.57 atm, critical volume 276 cm /mol practically insoluble in water soluble in alcohol, ether, chloroform and benzene. 

Colorless liquid density 1.879 g/cm at 20°C and 1.844 g/cm at 30°C refractive index 1.464 boils at 86.5°C solidifies at -49.5°C decomposes in water soluble in alcohol, ether, benzene, chloroform and carbon tetrachloride insoluble in concentrated hydrochloric and sulfuric acids. 

Colorless liquid burns with orange flame with green margin refractive index 1.5198 density 1.653 g/mL at 20°C insoluble in water slightly soluble in ethanol soluble in benzene, toluene, gasoline, and petroleum ether. 

Colorless fuming liquid pungent odor refractive index 1.516 at 14°C density 1.574g/mL at 21°C hods at 76°C freezes at -112°C decomposes in water soluble in benzene, carbon disulfide, ether and chloroform and other halo-genated organic solvents. 

Pale yellow or colorless liquid corrosive refractive index 1.651 at 20°C density 2.42 g/mL at 22°C freezes at 8.5°C boils at 176.4°C decomposes at 176.4°C decomposes in water forming hydrochloric acid and selenious acid soluble in carbon disulfide, carbon tetrachloride, chloroform, benzene, and toluene. 

Silvery needles refractive index 1.470 density 0.92 g/cm decomposes at 800°C decomposes explosively in water reacts violently with lower alco-hols dissolves in molten sodium and molten sodium hydroxide insoluble in liquid ammonia, benzene, carbon tetrachloride and carbon disulfide. 

Yellowish red oily liquid pungent penetrating odor fumes in air refractive index 1.670 at 20°C density 1.69 g/mL dipole moment 1.60 dielectric constant 4.9 at 22°C freezes at -77°C boils at 137°C reacts with water soluble in ethanol, benzene, ether, chloroform, and carbon tetrachloride dissolves sulfur at ambient temperature (67 g/100 g sulfur chloride). 

Pale yellow to red fuming liquid suffocating odor refractive index 1.517 at 20°C density 1.631 g/mL at 20°C freezes at -101°C bods at 75.6°C decomposes at 140°C decomposes in water soluble in benzene, chloroform, and carbon tetrachloride. 

Colorless, mobde hquid turns yellow on standing very pungent odor refractive index 1.4437 at 20°C density 1.667 g/mL at 20°C vapors heavier than air, vapor density 4.7 (air=l) melts at -51°C bods at 69.4°C sparingly soluble in water, decomposing slowly to sulfuric and hydrochloric acids forms a hydrate S02C12 I5H2O with ice-cold water miscible with benzene, toluene, chloroform, carbon tetrachloride, and glacial acetic acid decomposed by alkalies (violent reaction occurs)... 

Uping step changes in the concentration of benzene, the response was correlated with the calculated refractive index difference (ARI) at an attenuation of 4x. 

A general account of dipole-moment measurements and the use of these in conformational analysis has been given.3 At the University of East Anglia, for a study of the conformational equilibria of piperidines,119 121 electronic polarizations were estimated from tabulated bond polarizations122 (neglecting contributions of atomic polarization to the total polarization) or determined from refractive-index measurements. Most measurements were carried out in benzene or cyclohexane. 

DLS- 700S light scattering photometer at 633nm, calibrated with benzene. The optical clarification was performed with teflon filters. The specific refractive index increment (dn/dc) was obtained with Chromatix KMX-16 reffactometer at the same wavelength, calibrated with NaCl solution. 

Refractive Index. The effect of mol wt (1400—4000) on the refractive index (RI) increment of PPG in benzene has been measured (167). The RI increments of polyglycols containing aliphatic ether moieties are negative drf/dc (mL/g) = —0.055. A plot of RI vs 1/M is linear and approaches the value for PO itself (109). The RI, density, and viscosity of PPG—salt complexes, which maybe useful as polymer electrolytes in batteries and fuel cells have been measured (168). The variation of RI with temperature and salt concentration was measured for complexes formed with PPG and some sodium and lithium salts. Generally, the RI decreases with temperature, with the rate of change increasing as the concentration increases. 

Detector Compatibility A solvent must be carefully chosen to avoid interference with the detector. Most UV detectors monitor the column effluent at 254 nm. Any UV-absorbing solvent, such as benzene or olefins, would be unacceptable because of high background. Since refractometer detectors monitor the difference in refractive index between solvent and column effluent, a greater difference leads to greater ability to detect the solute. 

Methylene iodide [75-11-6], CH2I2, also known as diio dome thane, mol wt 267.87, 94.76% I, mp 6.0°C, and bp 181°C, is a very heavy colorless liquid. It has a density of 3.325 g/mL at 20°C and a refractive index of 1.7538 at 4°C. It darkens in contact with air, moisture, and light. Its solubility in water is 1.42 g/100 g H20 at 20°C it is soluble in alcohol, chloroform, benzene, and ether. Methylene iodide is prepared by reaction of sodium arsenite and iodoform with sodium hydroxide reaction of iodine, sodium ethoxide, and hydroiodic acid on iodoform the oxidation of iodoacetic acid with potassium persulfate and by reaction of potassium iodide and methylene chloride (124,125). Diiodoform is used for determining the density and refractive index of minerals. It is also used as a starting material in the manufacture of x-ray contrast media and other synthetic pharmaceuticals (qv). 

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