Power drying

This powerful drying agent is suitable for use with hydrogen, argon, helium, nitrogen, hydrocarbons, chlorinated hydrocarbons, esters and higher alcohols. 

Recover the acetate by treating the filtered reaction mixture with dilute sulfuric acid, and then filter-off the precipitated calcium sulfate. Then, distill the mixture at 110 Celsius to recover the acetic acid formed by the addition of sulfuric acid. Note if using hydrochloric acid instead of sulfuric acid, evaporate the left over reaction mixture to dryness after the distillation (to remove acetic acid), so as to recover the calcium chloride. Calcium chloride can be heated using a Bunsen burner so as to form anhydrous calcium chloride, which makes a powerful drying agent. Second note acetic acid is a useful by-product and can be used in a variety of applications. 

Phosphoric oxide has also an exceptionally high affinity of hydration, on which account it is universally used, where its chemical properties permit, as the most powerful drying agent for neutral or acid gases and liquids and also in desiccators. The heat of hydration of crystalline P205 is given as 44-6 Cals.,8 40-8 Cals.9 The amorphous variety when dissolved in much w-ater evolved 33-8 Cals, and the vitreous variety 29-1 Cals.10 Hence heat is evolved when the crystalline variety is transformed into the amorphous variety. 

Venus upper atmosphere is even drier than the lower atmosphere, and the average water-vapor mixing ratio above the clouds is only a few ppmv. The very low H2O mixing ratios were hard to explain until it was realized that Venus clouds are 75% sulfuric acid, which is a powerful drying agent. When dissolved in the acid, most of the water reacts with H2SO4 to form hydronium (HaO ) and bisulfate (HSO4) ions. As a result, the concentrations of free H2O in the acid solution and in the vapor over the acid are extremely low. The partial pressure of water at Venus cloud tops is lower than that over water ice at the same temperature. Thus, the clouds are responsible for the extreme dryness of Venus upper atmosphere, and play an important role in the photochemical stability of Venus atmosphere (see Section 1.19.3.3). 

Common to all available instruments are small particle numbers, which result in poor statistics. Thus recent developments have yielded a combination of powerful dry and wet dispersion with high-speed image capturing. Particle numbers up to 10 can now be acquired in a few minutes. Size and shape analysis is available at low statistical errors [W. Witt, U. Kohler, and J. List, Direct Imaging of Very Fast Particles Opens the Application of the Powerful (Dry) Dispersion for Size and Shape Characterization, PARTEC 2004, NUrnberg]. 

The most powerful drying agents are sodium and phosphorus pentoxide. The use of the former is evidently limited to those substances which do not react with the metal. Sodium is used to remove the last traces of water only, the substances being previously dried with calcium chloride which removes most of the water. 

Once the microscope has been set up as above, the slide containing the specimen should be placed on the stage and clipped in firmly. The slide should be viewed using a low power dry objective and a suitable field for further examination should be found by moving the slide in a horizontal plane. 

Thionyl chloride, SOCI2, is used as a very powerful drying agent in many synthetic chemistry experiments in which the presence of even small amounts of water would be detrimental. The unbalanced chemical equation is... 

Its structure can be viewed as that of P4O6 with another O atom bonded to each P atom (Figure 14.10B). P4O10 is a powerful drying agent. 

For the preparation of samples suitable for electrical measurements, special types of purification methods are employed. Reduction of the self-conductivity of the sample requires removal of traces of water and of particles from the liquid samples and from the walls of the test cell and filling tubes. Powerful drying agents used are activated silica gel or molecular sieves, phosphorus pentoxide, or alkali metals, especially sodium-potassium alloys. The liquid samples are either percolated through columns of silica gel or molecular sieves in an atmosphere of dry argon or nitrogen gas, or they are refluxed in a container with sodium potassium alloys for many hours. In order to remove adsorbed water from the walls of the test equipment, circulation of purified liquid and continuous drying are necessary. 

P., 2007. Microwave convective drying of plant foods at constant and variable microwave power. Drying Technol. 25 1149-1153. 

When they revealed the incomparable truth, they put to shame every wisdom of the gods, and their fieimarmene was discovered to be condemnable their power dried up, their dominion was destroyed, and their pronoia [and] their glories became [empty]. (Prig. Wld 125,25-32)... 

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