Volume of liquid

The V/L ratio is a volatility criterion seldom used in France but is used in Japan and in the United States where it has been standardized as ASTM D 2533. At a given temperature and pressure, the V/L ratio represents the volume of vapor formed per unit volume of liquid taken initially at 0°C. 

The diagram (Fig. 5.21) shows that as the pressure is reduced below the dew point, the volume of liquid in the two phase mixture initially increases. This contradicts the common observation of the fraction of liquids in a volatile mixture reducing as the pressure is dropped (vaporisation), and explains why the fluids are sometimes referred to as retrograde gas condensates. 

A second ideal model for adhesion is that of a liquid wetting two plates, forming a circular meniscus, as illustrated in Fig. XII-13. Here a Laplace pressure P = 2yz.A (h ws the plates together and, for a given volume of liquid. 

The material to be steam-distilled (mixed with some water if a solid compound, but not otherwise) is placed in C, and a vigorous current of steam blown in from D. The mixture in C is thus rapidly heated, and the vapour of the organic compound mixed with steam passes over and is condensed in E. For distillations on a small scale it is not necessary to heat C if, however, the flask C contains a large volume of material or material which requires prolonged distillation, it should be heated by a Bunsen burner, otherwise the steady condensation of steam in C will produce too great a volume of liquid. 

The transference of a liquid from one vessel to another is best carried out by means of a dropping pipette A (Fig. 30). For measuring out a definite volume of liquid it is obviously an advantage to have a calibrated pipette B (Fig. 30) of i or 5 ml. total capacity. Alternatively, semi-micro burettes reading to 0 02 ml. are particularly convenient for class work. 

Claisen flasks with fractionating side arms (see Figs. II, 24, 2-5) may be employed for comparatively small volumes of liquid. 

Fig. II, 37, 2 depicts the apparatus for dealing with comparatively small volumes of liquid. The essential feature is the special condenser with a take-off tube. A few small pieces of porous porcelain are introduced and the flask is heated either on a water bath or upon an electric hot plate. The assembly is also useful in the recrystaUisation of compounds which dissolve slowly excess of solvent may be employed, and the excess of solvent subsequently removed by distillation.

The set-up of Fig. 11, 41, 3 ensures the complete condensation of the steam when a rapid flow of steam is necessary for satisfactory results, and is useful in the distillation of large volumes of liquids of low vapour pressure, such as nitrobenzene. Thus the flask A containing the mixture may be of 3-litre capacity and B may be a 1-litre flask the latter is cooled by a stream of water, which is collected in a funnel and conducted to the sink. The receiver C must be of proportionate size all stoppers... 

When the volume of liquid in the flask is small, it is advisable to arrange the apparatus for distillation under reduced pressure (water pump) in order to completely separate the allyl cyanide from the solid residue. The final tarry residue may be removed by treatment with concentrated nitric acid, followed by water. 

Phenylacetylene. Support a 5-litre glass Dewar flask in a wooden case. Equip the flask with a lid of clear Perspex, provided with suitable apertures for a mechanical stirrer, introducing solids (e.g., sodium) or hquids, a calibrated dip stick for measuring the volume of liquid in the Dewar vessel, a gas mlet tube and an ammonia inlet arrange for an electric light to shine downwards into the flask. 

A liquid may be transferred from one vessel to another with a dropper pipette (Fig. XII, 1, 2, a or b). If the dropper pipette is calibrated, it may be employed for measuring out a definite volume of liquid. 

Fig. XII, 2, 1). For very small volumes of liquid either of the apparatus depicted in Fig. XII, 2, 10, incorporating a cold finger condenser may be employed subsequent distillation (or steam distillation) is a facile...

If the region FGH of the isotherm represents the filling of all the pores with liquid adsorbate, then the amount adsorbed along to plateau FGH, when expressed as a volume of liquid (by use of the normal liquid density) should be the same for all adsorptives on a given porous solid. This prediction is embodied in a generalization put forward many years ago by Gurvitsch and usually known as the Gurvitsch rule. 

Uptake at saturation by a ferric oxide gel at 25°C, calculated as a volume of liquid (v,)... 

Fig. 3.2 Adsorption isotherms for argon and nitrogen at 78 K and for n-butane at 273 K on porous glass No. 3. Open symbols, adsorption solid symbols, desorption (courtesy Emmett and Cines). The uptake at saturation (calculate as volume of liquid) was as follows argon at 78 K, 00452 nitrogen at 78 K, 00455 butane at 273 K, 00434cm g .

If now 5K is the total amount of adsorbate (read off from the isotherm and expressed as a volume of liquid) which is released during the stage i, then the volume of cores emptied during the stage must be... 

Evidence of a different kind is furnished by the fact that the Gurvitsch rule (p. 113) is often obeyed by systems showing Type I isotherms " the amounts of different adsorptives taken up by a given adsorbent, when expressed as a volume of liquid, agree within a few per cent. The order of agreement is illustrated by the typical examples in Table 4.1 for the adsorption of n-alkanes on ammonium phosphomolybdate, and in Table 4.2 which refers to a variety of adsorptives on a silica gel. It must be admitted, however, that there are cases where considerable deviations from the Gurvitsch mle are found, even though the isotherms are of Type 1. Thus, in Table 4.3 the variation in values of the saturation uptake is far outside... 

Values of the uptake at saturation, of butane, carbon dioxide and nitrogen, by a sample of carbon, expressed as a volume of liquid v,. The carbon had been "burnt off" to different extents by heating in oxygen at 500°C on a sorption... 

The term nebulizer is used generally as a description for any spraying device, such as the hair spray mentioned above. It is normally applied to any means of forming an aerosol spray in which a volume of liquid is broken into a mist of vapor and small droplets and possibly even solid matter. There is a variety of nebulizer designs for transporting a solution of analyte in droplet form to a plasma torch in ICP/MS and to the inlet/ionization sources used in electrospray and mass spectrometry (ES/MS) and atmospheric-pressure chemical ionization and mass spectrometry (APCI/MS). 

In Chap. 9 we shall examine the flow of a solution through a capillary tube. The rate of volume delivery in that case is given by Poiseuille s law [Eq. (9.29)], which states that the time required for a constant volume of liquid to drain out of the capillary is proportional to r jp. Accordingly, the viscosity is proportional to the product pt, and when the delivery times for two liquids are compared in the same capillary. 

Next we consider replacing the sandwiched fluid with the same liquid in which solid spheres are suspended at a volume fraction unit volume of liquid-a suspension of spheres in this case-the total volume of the spheres is also 0. We begin by considering the velocity gradient if the velocity of the top surface is to have the same value as in the case of the... 

Equation (9.28) describes the velocity with which a cylindrical shell of liquid moves through a capillary under stationary-state conditions. This velocity times the cross-sectional area of the shell gives the incremental volume of liquid dV which is delivered from the capillary in an interval of time At. The total volume delivered in this interval AV is obtained by integrating this product over all values of r ... 

G. Le Bas, The Molecular Volumes of Liquid Chemical Compounds, Longmans, Gieen, New York, 1915. 

LHSV (liquid hourly space velocity) = (volume of liquid feed at 60°F/h)/(fF of reactor) = SCFH hquid feed/fF. 

When a tank volume cannot be calculated or when greater precision is required, calibration may be necessaiy. This is done by draining (or filling) the tank and measuring the volume of liquid. The... 

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