Liquid gases, boiling points

Cas Boiling point Liquid density Volume ratio gas Vapour Critical... 

TABLE 4.1. Boiling Points and Gas-Liquid Equilibrium Characteristics (Henry s Law Constants) for Both Odorous and Nonodorous Compounds in Water at 25°C (Thibodeaux, 1996 Sander, 2000). 

This chapter focuses on gas-liquid chromatography, in which compounds in a sample are separated based on vapor pressures and differences in affinity for the stationary phase (a high boiling point liquid) versus the gaseous mobile phase. The time between sample injection and detection of the individual compound eluting from the column is called the retention time. Compounds that have limited solubility in the stationary phase will exit the column quickly as a large proportion will remain in the mobile phase. Compounds with polarity similar to that of the stationary phase will have longer retention times and potentially broader peaks, due to increased interaction with the stationary phase. 

A low-boiling-point liquid, in boiling off, has a good heat transfer coefficient to help cool the wall and buy time. Calculate the time required to heat up the liquid and vaporize the inventory. If the time is less than 15 minutes treat the vessel as being gas filled. If the time is more than 15-20 minutes treat it as a safe condition. However, in this event, be sure to check the final pressure of the vessel with the last drop of liquid for PSV sizing. 

Better yields of carbon black are obtained by improved separation of the combustion function from the carbon-forming function, as is accomplished in the newer furnace black processes. This approach enables gas oil (high boiling point liquid petroleum fractions) or natural gas to be used to produce carbon black. The cooling function from 1,400°C to about 200°C is accomplished by direct water sprays. The product is removed from the gas stream via a combination of cyclone collectors and glass or Teflon fiber bag filters. One tonne of furnace black is obtained from 5,300 to 7, OOOm (1 atm 15.6°C) of natural gas, or 1,400-2,800 L of gas oil corresponding to 50-70% yields. Oil-based furnace black now supplies about 90% of the current carbon black market, although the special features of the product from small-scale processors still contribute some product [4]. 

A heating mantle has a hemispherical cavity that is used to heat round-bottom flasks. A Bunsen burner is designed to burn natural gas. Bunsen burners are useful for heating high-boiling point liquids,... 

The three straight lines show that the volume of each gas is directly proportional to its Kelvin temperature. The solid part of each line represents actual data. Part of each line is dashed because, as you recall from Chapter 10, when the temperature of a gas falls below its boiling point, a gas condenses to a liquid. 

Establishing the pipeline fluid conditions liquid at temperatures below the atmospheric-pressure boiling point liquified gas at temperatures above the atmospheric-pressure boiling point or gas, temperature, and pressure. 

Strategy At the boiling point, liquid and gas phase ethanol are at equilibrium, so AG = 0. From Equation... 

Strategy At the boiling point, liquid and gas phase ethanol ate at equilibrium, so AG = 0. From Equation (18. 10) of the text, we have AG = 0 = AH -TASot AS= AH/T. To calculate the entropy change for the liquid ethanol -> gas ethanol transition, we write ASVap = A//vap/ What temperature unit should we use ... 

The heat input to diyers is to a gas and as such takes place over a range of temperatures. Moreover, the gas is heated to a temperature higher than the boiling point of the liquid to be evaporated. The exhaust gases from the dryer will be at a lower temperature than the inlet, but again, the heat available in the exhaust will be available over a range of temperatures. The thermal characteristics of dryers tend to be design-specific and quite difierent in nature from both distillation and evaporation. 

Figure A2.5.5. Phase diagrams for two-eomponent systems with deviations from ideal behaviour (temperature T versus mole fraetion v at eonstant pressure). Liquid-gas phase diagrams with maximum (a) and minimum (b) boiling mixtures (azeotropes), (e) Liquid-liquid phase separation, with a eoexistenee eurve and a eritieal point.

Liquid ammonia. This can be prepared by compressing ammonia gas. It has a boiling point of 240 K and is an excellent solvent for many inorganic and organic substances as well as for the alkali metals. Liquid ammonia is slightly ionised. ... 

Phosphine is a colourless gas at room temperature, boiling point 183K. with an unpleasant odour it is extremely poisonous. Like ammonia, phosphine has an essentially tetrahedral structure with one position occupied by a lone pair of electrons. Phosphorus, however, is a larger atom than nitrogen and the lone pair of electrons on the phosphorus are much less concentrated in space. Thus phosphine has a very much smaller dipole moment than ammonia. Hence phosphine is not associated (like ammonia) in the liquid state (see data in Table 9.2) and it is only sparingly soluble in water. 

---