Volume Expansion of Liquids

If Vo is the volume at 0°, then at t° the expansion formula is Vf = Vo(l + a + + yt ). The table gives values of a, p, and y, and of C, the true coefficient of volume expansion at 20° for some liquids and solutions. The temperature range of the observation is At. Values for the coefficient of volume expansion of liquids can be derived from the tables of specific volumes of the saturated liquid given as a function of temperature later in this section. C = (dV/dt)IVQ 

Gherman and Sherman,/. Am. Chem. Soc., 50, 1119 (1928). (An obvious error in their equation has been corrected.) 

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The mean volume expansivity of liquid mercury is 18.2 x 10" expansivity is ... 

Avolume of mercury of 10 m at 20°C is contained in glass bulb, with expansion taken up by the mercury moving into a capillary 0.5 mm diameter, similar to a mercury thermometer. The aim is to allow the mercury to expand and complete an electrical circuit and activate a cooling device. If the circuit contact is 5 mm above the mercury level at 20 °C, what temperature will activate the device The mean volume expansivity of liquid mercury is 18.2 x 10 K . ... 

Problem 2.31 Use the Racket equation to estimate the volume expansivity of liquid ethanol at 25 °C. State your assumptions clearly. 

In the investigations carried out by one of the authors [56], an attempt was made to examine the conditions for the thermal volume expansivity of PET fibers. Within the framework of these investigations, aas was determined from the hydrostatic weight measurements using n-heptan as a liquid. The sought aas values have been calculated from the equation ... 

Because the gas always flows at a velocity greater than that of the liquid, the in situ volumetric fraction of liquid at any point in a pipeline will be greater than the input volume fraction of liquid furthermore it will progressively change along the length of the pipe as a result of expansion of the gas. 

Glass-packaged liquid products may break owing to the volume expansion of the solution when it freezes. It is especially important that the pharmacist fully advise the patient on proper storage and use of ophthalmic products to ensure their integrity and their safe and efficacious use. 

Thermal Expansion Coefficient for Liquids The coefficient of volume expansion for liquids is the ratio of the change in volume per degree to the volume at -17.8°F (0°C). The value of the coefficient varies with temperature. 

Expansion of Liquids.—In liquids, the expansion produced by heat is much more marked than in Bolide they also differ among themselves in the amount of expansion produced by equal increments of heat. The most volatile liquids, or those of which the boiling point iB low, are found to be the most expansible under the influence of an increase of caloric, as may be observed from the appended table, showing the comparative increase in volume of several liquids when heated from 32° to 212°,—-... 

The Volume Expansion of Alkali Metals in Liquid Ammonia... 

The volume expansions of alkali metals in liquid ammonia are discussed in the light of the current available data. Special emphasis is made of the anomalous volume minimum found with sodium-ammonia and potassium-ammonia solutions. Recent studies of potassium in ammonia at —34° C. were found to exhibit a large minimum in the volume expansion, AV, vs. concentration curve. The results of these findings were compared with the previous results of potassium in ammonia at —45° C. The volume minimum was found to be temperature dependent in that the depth of the minimum increased and shifted to higher concentrations with increasing temperature. No temperature effect was observed on either side of the minimum. These findings are discussed in light of the Arnold and Patterson and Symons models for metal-ammonia solutions. 

Let us again review the previous findings for the volume expansion of sodium and potassium in liquid ammonia. Filbert (8) reported a volume minimum for sodium in ammonia at —46° C. at approximately 0.03N. Orgell (21) confirmed the existence of this minimum for sodium in ammonia at —45° C. and extended his study to potassium in ammonia at the same temperature. Potassium-ammonia solutions were found to exhibit a minimum at O.OliV which was quite sharp and not nearly as broad as the minimum for sodium at —45° C. More recently, Brendley has investigated the volume expansion of potassium in ammonia at —34° C. Once again a pronounced minimum was found. The potassium data at —45° C. and —34° C. showed differences in the position and... 

Figure 7. Volume expansion of potassium in liquid ammonia at —45°C.

Figure 9. A comparison of the volume expansion of potassium in liquid ammonia as a function of the logarithm of the concentration...

When a saturated liquid is expanded in a turbine some of the liquid vaporizes. A turbine properly designed for expansion of liquids cannot handle the much larger volumes resulting from the formation of vapor. For example, if saturated liquid at 5 bar expands isentropically to 1 bar, the fraction of the original liquid that vaporizes is found as follows ... 

Gas anti-solvent fractionation was carried out using C02 on mixtures of lecithin/Soya oil/hexane coriander seed triglycerides/essential oil/hexane and pure components of the mixtures. Separation of the mixtures into individual components was demonstrated at a laboratory scale. The degree of separation possible was a function of the volume expansion of the liquid solvent phase. The pressure/volume expansion at which a pure component precipitated was qualitatively related to its solubility in supercritical C02. The volume expansion was a function of temperature and pressure. The pressure required to reach a certain volume expansion increased as both the temperature and triglyceride content increased. 

The importance of selecting gravimetry instead of volumetry to measure liquid amounts in the pharmaceutical industry of liquid dosage forms is well illustrated by the volume contraction of water-ethanol and volume expansion of ethyl acetate-carbon disulfide liquid mixtures as well as a CS2-ethyl acetate system. The National Formulary (NF) diluted alcohol is a typical example of the volume nonadditivity of liquid mixtures [29], This solution is prepared by mixing equal volumes of alcohol [U.S. Pharmacopeia (USP)] USP and purified water (USP). The final volume of this solution is about 3% less than the sum of the individual volumes because of the contraction due to the mixing phenomenon [1], In addition, molecular interactions of surfactants in mixed monolayers at the air-aqueous solution interface and in mixed micelles in aqueous media also cause some contraction of volume upon mixing [30],... 

TEM observations of the oxidized scale have revealed mullite grains with transgranular cracks, a phenomenon that is not surprising when one considers that the oxidation of SiC produces a volume expansion of 100%. When the reaction product contains a solid as well as a liquid product, as in the present situation, the volume expansion can be accommodated by squeezing out the liquid phase, resulting in a liquid cap on top of the solid reaction products. This has been observed by Luthra and Park,13 and is apparent in the micrograph shown in Fig. 8.5. 

A mercury thermometer is based on the differential volume thermal expansion of liquid mercury (about 1.8 X 10 and glass (about 0.2 X 10 " K ). In the manu-... 

The number of holes per unit volume can be expressed in terms of the known volume expansion of a mole of the liquid at the melting point A divided by the mean... 

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