Mm mercury

Change in boiling point for every 10 mm. mercury pressure at 760 20 mm. 

The mercury barometer (Fig. 10-11) indicates directly the absolute pressure of the atmosphere in terms of height of the mercuiy column. Normal (standard) barometric pressure is 101.325 kPa by definition. Equivalents of this pressure in other units are 760 mm mercury (at 0°C), 29.921 iuHg (at 0°C), 14.696 IbFin, and 1 atm. For cases in which barometer readings, when expressed by the height of a mercuiy column, must be corrected to standard temperature (usually 0°C), appropriate temperature correction factors are given in ASME PTC, op. cit., pp. 23-26 and Weast, Handbook of Chemistty and Physics, 59th ed., Chemical Rubber, Cleveland, 1978-1979, pp. E39-E41. 

Boiling Point (BP) — the temperature at which a liquid changes to gas under standard atmospheric pressure (760 mm mercury). The BP of water is 100°C, while the BPs of ethyl alcohol and n-hexane are 78.4°C and 68.7°C, respectively. Lowering the atmospheric pressure (e.g., by applying a vacuum) will lower the BP conversely, higher pressures result in elevated boiling points. 

Chlorine dioxide is a yellow-green gas and soluble in water at room temperature to about 2.9 g/1 chlorine dioxide (at 30 mm mercury partial pressure) or more than 10 g/1 in chilled water. The boiling point of liquid chlorine dioxide is 11° C the melting point is - 59° C. Chlorine dioxide gas has a specific gravity of 2.4. The oxidant is used in a water solution and is five times more soluble in water than... 

A centrifugal pump is to be used to extract water from a condenser in which the vacuum is 640 mm of mercury. At the rated discharge the net positive suction head must be at least 3 m above the cavitation vapour pressure of 710 mm mercury vacuum. If losses in the suction pipe account for a head of 1.5 m. what must be the least height of the liquid level in the condenser above the pump inlet ... 

Carruth, G.F., Kobayashi, R. (1973) Vapor pressure of normal paraffins ethane through n-decanc from their triple points to about 10 mm mercury. J. Chem. Eng. Data 18(2), 115-126. 

Quarts (U.S. liquid) Cubic meters 9.464 x 10-4 Torr (mm. mercury, 0°C.) Newtons per square meter 133.32... 

In the ester interchange method a mixture of bisphenol A and diphenylcarbonate along with a basic catalyst like lithium hydride is melted and stirred at 150°C under nitrogen. Later on, when the temperature is raised to 210°C at 20 mm mercury pressure most of the phenol formed gets distilled off. In the last stage the temperature is raised to 300°C at 1 mm Hg. 

For gases and vapors, exposure concentrations are traditionally expressed in parts per million (ppm). The calculation for the ppm of a gas or vapor in an air sample is based on Avogadro s Law, which states that Equal volumes contain equal numbers of molecules under the same temperature and pressure. In other words, under standard temperature and pressure (STP), one gram-molecular weight (mole) of any gas under a pressure of one atmosphere (equivalent to the height of 760 mm mercury) and a temperature of 273 K has the same number of molecules and occupies the same volume of 22.4 liters. However, under ambient conditions, the volume of 22.4 liters has to be corrected to a larger volume based on Charles Law, which states that at constant pressure the volume of gas varies directly with the absolute temperature. Thus, at a room temperature of 25° C, one mole of a gas occupies a volume of 24.5 liters. 

It is common to find vapour pressures quoted in millimetres (mm) mercury (Hg) in older papers, although sometimes the identical unit Torr is cited instead. In both cases, the conversion to the SI unit, the Pascal (Pa), is simply ... 

The torr is included in the table only to facilitate the transition from this familiar unit to the statutory units N m, mbar and bar. In future the pressure units tor, mm water column, mm mercury column (mm Hg), % vacuum, technical atmosphere (at), physicalatmosphene (atm), atmosphere absolute (ata), pressure above atmospheric and pressure below atmospheric may no longer be used. Reference is made to DIN 1314 in this context. 2) The unit Newton divided by square meters (N m ) is also designated as Pascal (Pa) 1 N m = 1 Pa. Newton divided by square meters or Pascal is the SI unit for the pressure of fluids. 3) 1 torr = 4/3 mbar fl torr = 1 mbar. ... 

Table 7. Vapour pressure (in mm mercury) perature is also high and...

After evacuation, the vessel should be tilted into the horizontal position shown in Figure 14.4 and the stopcock should be turned to disconnect the pump, and then turned further to admit air to the vessel. The pressure of air acting on the mercury in the vessel pushes it into the reservoir and the capillary of the HMDE. If the pressure was previously decreased to 0.01 mm, mercury now fills the reservoir and capillary completely. The HMDE is now ready for use. By turning the screw a fixed angle, a known amount of mercury is pushed out, forming a drop. 

In voltammetry it is occasionally necessary to have a mercury electrode with a constant but fresh mercury surface. Such an electrode was developed by Heyrovsky [41-43] for oscillopolarography. It is usually made of a thick-walled capillary (6-7 mm o.d.) with an internal diameter of 1 to 2 mm, but at its end the diameter decreases to 0.1 mm. Mercury flows from the capillary in one stream, which is usually directed upward, out of the solution. If the cylindrical shape of the mercury stream is maintained along its length, the surface of the electrode will be A = 2nrci where rc is the radius of the capillary at its end and f is the length of the continuous stream of mercury in solution. The rate of mercury flow is approximately a hundredfold greater than for a classical DME (about 0.2 g/s or 0.7 kg/h). 

NaCl solution, improving the retention of penicillin residues. Penicillins were eluted from the SPE cartridge with MeCN or MeCN phosphate buffer. The eluate was allowed to react with 1-10 mM mercury chloride in the presence of 2 M 1,2,4-triazole or imidazole under slightly alkaline conditions (pH 8.5-9). The derivatization was performed at 65°C for at least 30 min, yielding penicillinic acid mercury mercaptide with UV absorption maximum at 325-345 nm (80,81). 

Figure 6.2. (A) Variations in %N (which is proportional to C density) with precipitation along the 11 °C isotherm in the Great Plains of the United States. The humidity factor (NSQ, Niederschlag-Sattigungsdefizit from the German, or Meyer s quotient) is the total annual precipitation (mm) divided by the absolute saturation deficit of air (mm mercury). All soils were developed on loess deposits from the last glacial maximum. (B) Change in %N with precipitation along the 19 °C isotherm. Note that relative C density (estimated by assuming that the C/N ratio of SOM is fairly constant) is lower at higher mean annual temperature. Reprinted with permission from Jenny, H. (1941). Factors of Soil Formation, Dover Publications, New York.

Benzaldehyde dimethylacetal (200 pi, 1.33 mmol) and a catalytic amount of p-toluenesulfonic acid (37 mg) are added to methyl (2R,3S)-3-(4-nitrobenzenesulfonamido)-3-phenyl-2-hydroxypropionate (315 mg, 0.83 mmol) in toluene 5 ml. The mixture is heated at 100°C under reduced pressure (15 mm mercury) with no condenser. After 1 h the crude reaction mixture is diluted with ethyl acetate and washed with water (2 times). After drying the organic layer over magnesium sulfate the crude material is purified by column chormatography (silica gel eluting with ethyl acetate/cyclohexane, 35/65) to give the (2S,4S,5R)-2,4-diphenyl-3-(4-nitrobenzenesulfonamido)-5-methoxycarbonyl-l,3-oxazolidine, melting point 118°-120°C. 

Solution The barometric pressure is needed to determine vessel pressure from an open-ended manometer. A manometer reading is always a difference between two pressures. See 0005. One standard atmosphere is 760 mm mercury, but on a given day at a given location, the actual ambient pressure may vary. If the barometric pressure on the day of the experiment is 104 kPa, the pressure of the vessel is ... 

Pknown may be another vessel or the atmospheric pressure that is determined with a barometer. The difference in liquid levels Ah may be converted to a pressure (e.g., 760 mm mercury=1 atm). If the liquid level is higher on the Pknown side, Ah is added to Pknown to obtain Punknown If the liquid level is higher on the Punknown side as in the example shown, Ah is subtracted from Pknown to obtain Punknown-... 

Carbonic Acid.—Berthelot1 observed the decomposition into carbon monoxide and oxygen. The reaction is reversible, an equilibrium occurs, in which, however, the partially ozonized oxygen converts carbon monoxide into carbonic acid and a solid carbon suboxide, C4O3, which Brodie 2 had already formerly observed. Carbon dioxide, under a pressure of 3-10 mm. mercury, splits up very rapidly and up to 70 per cent, into carbon monoxide and oxygen (Norman Collie 3). 

Methyl Alcohol.—According to Maquenne,2 the vapor of methyl alcohol is decomposed by the silent discharge chiefly into methane and carbon monoxide some hydrogen, ethylene, and acetylene and very little carbonic acid, are also produced. The quantity of hydrogen increases with increasing pressure (from 3-100 mm. mercury pressure), that of the other products decreases ... 

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