Specific volume of water vapor

Fig. 1.2. Specific volume of water vapor as a function of the water vapor pressure. The temperature of the vapor in this diagram is that of the ice.

Problem Assuming the heat of vaporization of water to be constant at 539 cal. g., calculate the temperature at which water will boil under a pressure of 77.0 cm., the boiling point being 100.00 C at 76.0 cm. The specific volume of water vapor at 100 C and 76.5 cm. pressure is 1664 cc. g. and that of liquid water is (approximately) 1 cc. g. ... 

Vent gas temperature [VT] 170F 76.7C Specific volume of water vapor 170°F 25.3 fttlb ... 

Humid volumes are given by the curves entitled Volume mVkg diy air. The volumes are plotted as func tions of absolute humidity and temperature. The difference between dry-air specific volume and humid-air volume at a given temperature is the volume of water vapor. 

Refer to Fig. 3.5. The vertical lines between the curves are lines of constant temperature connecting the vapor and liquid phases, which are in equilibrium. As the temperature increases, the specific volumes of the vapor and liquid approach each other until finally at 374.14 C, the values are the same. At the critical state water undergoes a transition from liquid to vapor without the appearance of a distinct two-phase region. If you watch a liquid held at or above the critical temperature and expand its volume, you cannot tell when the liquid becomes a vapor, because no interfece is formed between the phases—no liquid surfece can be seen. This phenomenon occurs at such a high pressure and temperature for water that it is outside your everyday experience. 

Compare the values of AH and AE for the vaporization of 1 mole of water at 100 C and 1 atm. pressure. The heat of vaporization of water is 639 cal. g. at the normal boiling point the specific volume of the vapor is then 1676 cc. g.", and that of the liquid is approximately unity. Suggest why the value of AE in this case is sometimes called the internal heat of vaporization. ... 

At 25 C, the vapor pressure of water is 23.76 mm. and the specific volume of the vapor under these conditions is 43,400 cc. g. Calculate the free energy change for the transfer of 1 mole of water from liquid at 25 C to vapor at unit fugacity. What error is involved in treating the vapor as an ideal gas (cf. Exercise 9, Chapter X) ... 

Another patent refers specifically to the manufacture of diphenyl from benzene in a novel and highly advantageous manner.1 The invention is based upon the discovery that the amount of diphenyl obtained from benzene can be very materially increased by subjecting the vaporized benzene to a temperature of 700° C. and a pressure of about 60 pounds per square inch in admixture with a diluent gas or vapor (23 parts volume of water vapor). The production of diphenyl can be further promoted by treating the benzene in the presence of appropriate substances which provide cracking surfaces, such as, for example, pumice. 

Specific heat of water vapor at constant volume, cIIW 1463 Jkg- K-1 26.33 Jmor1 K 1... 

Figure 28 shows the key features of the humidity chart. The chart consists of the following four parameters plotted as ordinates against temperature on the abscissas (1) Humidity H, as pounds of water per pound of dry air, for air of various relative humidities (2) Specific volume, as cubic feet of dry air per pound of dry air (3) Saturated volume in units of cubic feet of saturated mixture per pound of dry air and (4) latent heat of vaporization (r) in units of Btu per pound of water vaporized. The chart also shows plotted hiunid heat (s) as abscissa versus the humidity (H) as ordinates, and adiabatic humidification curves (i.e., humidity versus temperature). Figure 28 represents mixtures of dry air and water vapor, whereby the total pressure of the mixture is taken as normal barometric. Defining the actual pressure of the water vapor in the mixture as p (in units of mm of mercury), the pressure of the dry air is simply 760 - p. The molal ratio of water vapor to air is p/(760-p), and hence the mass ratio is ... 

As defined earlier, the saturated volume is on a basis of 1 lb of dry air, and equals the sum of the specific volume of the dry air plus the volume of the water vapor... 

The practice of free-phase NAPL recovery, soil vapor extraction, and hydraulic containment at remediation sites almost always generates some volume of water contaminated with dissolved fractions. Depending on the size of the facility and the scale of the recovery and restoration project, the amount of groundwater coproduced can possibly exceed 1000 gal/min. Handling of these volumes of contaminated water can be very expensive if treatment is required prior to disposal or reinjection. Treatment of water derived from sites contaminated by other organic chemicals will involve adaptations of these procedures to the specific situation. 

If formula of deton (or expin) of an individual expl like NG or TNT is known, it is easy to calculate VD, which is specific volume of gases in liters, produced on expin of 1kg of expl, calcd to 0°C 760mm with water vapor... 

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