Liquids, mixed, boiling points pressures

Schimmel Co. attempted to acetylise the alcohol by means of acetic anhydride, but the reaction product only showed 5 per cent, of ester, which was not submitted to further examination. The bulk of the alcohol had been converted into a hydrocarbon, with loss of water. Ninety per cent, formic acid is most suitable for splitting off water. Gne hundred grams of the sesquiterpene alcohol were heated to boiling-point with three times the quantity of formic acid, well shaken, and, after cooling, mixed with water. The layer of oil removed from the liquid was freed fi-om resinous impurities by steam-distillation, and then fractionated at atmo.spheric pressure. It was then found to consist of a mixture of dextro-rotatory and laevo-rotatory hydrocarbons. By repeated fractional distillation, partly in vacuo, partly at ordinary pressure, it was possible to separate two isomeric sesquiterpenes, which, after treatment with aqueous alkali, and distillation over metallic sodium, showed the following physical constants —... 

To obtain the free base, 34 g (0.256 mol) of N-ethyl-3-piperidinol and 20 g (0.22 mol) of diphenylacetyl chloride were mixed in 80 cc of isopropanol and the solution was refluxed for 2 hours. The isopropanol was evaporated in vacuo at 30 mm pressure, the residue was dissolved in 150 cc of water and the aqueous solution was extracted several times with ether. The aqueous solution was then neutralized with potassium carbonate and extracted with ether. The ethereal solution was dried over anhydrous potassium carbonate and the ether removed by distillation. The product was then distilled at its boiling point 180° to 181°C at 0.13 mm of mercury whereby 14 g of a clear yellow, viscous liquid was obtained. The nitrogen content for CjiHjjNOj was calculated as 4.33% and the nitrogen content found was 4.21%. 

Mix 400 mL of pure concentrated hydrochloric acid with 250-400 mL of distilled water so that the specific gravity of the resultant acid is 1.10 (test with a hydrometer). Insert a thermometer in the neck of a 1 L Pyrex distillation flask so that the bulb is just opposite the side tube, and attach a condenser to the side tube use an all-glass apparatus. Place 500 mL of the diluted acid in the flask, distil the liquid at a rate of about 3-4 mL min-1 and collect the distillate in a small Pyrex flask. From time to time pour the distillate into a 500 mL measuring cylinder. When 375 mL has been collected in the measuring cylinder, collect a further 50 mL in the small Pyrex flask watch the thermometer to see that the temperature remains constant. Remove the receiver and stopper it this contains the pure constant boiling point acid. Note the barometric pressure to the nearest millimetre at intervals during the distillation and take the mean value. Interpolate the concentration of the acid from Table 10.5. 

The final colligative property, osmotic pressure,24-29 is different from the others and is illustrated in Figure 2.2. In the case of vapor-pressure lowering and boiling-point elevation, a natural boundary separates the liquid and gas phases that are in equilibrium. A similar boundary exists between the solid and liquid phases in equilibrium with each other in melting-point-depression measurements. However, to establish a similar equilibrium between a solution and the pure solvent requires their separation by a semi-permeable membrane, as illustrated in the figure. Such membranes, typically cellulosic, permit transport of solvent but not solute. Furthermore, the flow of solvent is from the solvent compartment into the solution compartment. The simplest explanation of this is the increased entropy or disorder that accompanies the mixing of the transported solvent molecules with the polymer on the solution side of the membrane. Flow of liquid up the capillary on the left causes the solution to be at a hydrostatic pressure... 

Ethylbenzene (boiling point 136°C, density 0.8672, flash point 21°C) is a colorless liquid that is manufactured from benzene and ethylene by several modifications of the older mixed liquid-gas reaction system using aluminum chloride as a catalyst (Friedel-Crafts reaction). The reaction takes place in the gas phase over a fixed-bed unit at 370 C under a pressure of 1450 to 2850 kPa. Unchanged andpolyethylated materials are recirculated, making a yield of 98 percent possible. The catalyst operates several days before requiring regeneration. 

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