Liquified oxygen

Liquified gases are sometimes stored in well-insulated spherical containers that are vented to the atmosphere. Examples in the industry are the storage of liquid oxygen and liquid ammonia in spheres. If the radii of the inner and outer walls are r, and r, and the temperatures at these sections are T, and T, an expression for the steady-state heat loss from the walls of the container may be obtained. A key assumption is that the thermal conductivity of the insulation varies linearly with the temperature according to the relation ... 

Pyridine (250 ml), copper(I)chloride (4 g, technical quality) and diazabicydoundecene (5 ml, commercially available) are placed in the flask. The mixture is brought to 25 C and 1-butyne (-10 ml, p. 165), liquified in a trap cooled at -78 C, is quickly poured into the stirred solution. Oxygen is then introduced (- 200 ml/min) with vigorous agitation (an inlet tube equipped with a fritt should be used). The temperature of the solution is kept between 30 and 35 C (occasional cooling). When the exothermic reaction has subsided, the mixture is cooled to 25 0 an additional 10 ml of the total amount of 1.0 mol of butyne is poured into the solution, and the introduction of oxygen is continued. When, after addition of the last portion of butyne, the temperature has dropped to below 30 C, the contents of the cold trap (usually... 

Synonym Liquid Hydrogen Liquid Impure Camphor Liquid Nitrogen Liquid Nitrogen Dioxide Liquid Oxygen Liquid Petrolatum Liquified Phenol Litharge... 

Yet, for a number of reasons, helium had defied liquefaction. For one thing, while it was a major constituent of the sun and other stars, helium was difficult to find on earth. Even more important was the problem of its critical temperature, which seemed to be far colder than any temperature that had been attained and employed thus far. Chlorine, for example, was readily liquefied at a pressure of 100 pounds per square inch at a balmy 68° F. But even those gases with incredibly low critical temperatures had succumbed oxygen, liquified at -297.4° F nitrogen, -320° F neon, -410° F and hydrogen, -422° F. 

Oxygen is the most abundant substance in the universe. Krypton and xenon are so rare as almost to leave doubts as to their existence. Methane is practically insoluble in water. Ammonia is absorbed to the extent of 1,000 times the volume of water. Chlorine may be liquefied and solidified with very meager pressures, and at atmospheric temperature. It is doubtful if hydrogen or methane have ever been even liquified, certainly not without the most extreme conditions of pressure and refrigeration. 

Oxygen, Liquified Not pertinent Not pertinent Not pertinent Not pertinent... 

Oxygen, Liquified Not flammable Not flammable Not flanunable Not flammable Not pertinent Not pertinent Increases the intensity of the fire. Mixtures of liquid oxygen and any fuel are highly explosive Not pertinent Heat of water will vigorously vaporize liquid oxygen ... 

For the preparation of pure chlorine, b.p. — 34.157760 mm., d 25 1.565, d 30 1.551, d 20 1.524, see reference 4a. It usually suffices to pass chlorine through two wash-bottles containing concentrated sulfuric acid and, if necessary, through a CaO tube for removal of HC1 and thereafter over phosphorus pentoxide to remove water. To provide measured amounts of chlorine it is convenient to liquify it in a calibrated vessel cooled in an acetone-C02 bath. Chlorine largely free from oxygen and oxides of chlorine can be obtained from manganese dioxide hydrate and concentrated hydrochloric acid.5 c... 

Liquified gases such as ethylene, oxygen, nitrogen, and hydrogen are typically stored in double-wall spheres, where the inner tank is suspended from the outer tank by straps or cables and the annular space between the tanks is filled with insulation. I he outer tank is not subjected to the freezing temperatures and is thus designed as a standard carbon steel sphere. 

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