Liquid hydrogen, boiling point

Liquid helium, boiling point = —269 Liquid hydrogen, freezing point = —259... 

Vanadium oxytrichloride is a lemon-yellow liquid. Its boiling point is 124.5°C. at 736 mm. and 127.16°C. at 760 mm. It remains liquid at —77°. The vapor pressure at —77° is 4.1 mm. at 0°, 21 mm. and at 85°C., 270 mm. Its density in grams per milliliter is 1.854 at 0° and 1.811 at 32°C. At ordinary temperatures, it neither dissolves nor reacts with carbon, hydrogen, nitrogen, oxygen, silicon, tellurium, or metals except the alkali metals and antimony. The reactions with the alkali metals are explosive at characteristic temperatures, varying from 30°C. for cesium to 180°C. for sodium (lithium not determined). Small... 

Methyl(chloromethyl)dichlorosilane is a colourless motile liquid (the boiling point is 120 °C) with a pungent odour. It fumes in air and can be easily hydrolysed with water releasing hydrogen chloride. It can be easily dissolved in organic solvents. 

Silicon tetrachloride is a motile, colourless or light yellow liquid (the boiling point is 57.7 °C) with a pungent odour. It is soluble in dichloro-ethane, gasoline and other organic solvents. It combines with alcohols to form ethers of orthosilicon acid. It strongly fumes in air, because humidity hydrolyses it and releases hydrogen chloride vapours. 

Titanium tetrachloride is a colourless transparent liquid (the boiling point is 136 °C) it is easily decomposed with water forming hydrogen chloride and titanium dioxide. It joins the moisture in air to form white suffocating fumes, which are drops of hydrochloric acid. 

Phosphorus(V) sulfochloride is a colorless, fuming liquid with boiling point 125° and specific gravity 1.635. The alpha form solidifies at —40.8°, while the beta form solidifies at —36.2°.7 The compound hydrolyzes slowly in water and rapidly in alkaline solution. In water, the hydrolysis products are orthophosphoric acid, hydrochloric acid, and hydrogen sulfide. Phosphorus (Y) sulfochloride is soluble in benzene, carbon tetrachloride, carbon disulfide, and chloroform. It reacts with ethanol, yielding O-ethyl dichlorothiophosphate8 (synthesis 25). 

Equilibrium between the liquid and vapor phases of equilibrium hydrogen (boiling point of equilibrium hydrogen) 20.28 -252.87... 

Because of their inability to form hydrogen bonds, esters tend to be liquids with boiling points much lower than those of carboxyhc acids of similar molecular weights. 

Amides have hydrogen bonds between their molecules and so their boiling points are relatively high. For example, formamide is a liquid with boiling point 190°C while all other amides are white-crystalline solids. Since they are polar, they are water soluble. They do not react with acids and bases, though when heated slowly with water they are hydrolyzed. 

The two main forms of large-scale storage of hydrogen are compressed gas and cryogenic liquid. The boiling point of hydrogen under atmospheric pressure is at 20 K, which is —253 °C. Storing a liquid at this temperature requires the use of elaborately insulated vessels. 

When a pair of liquids have boiling points within 30 °C of one another, it is difficult to say which will evaporate more rapidly at room temperature. Alcohols, in particular, are slower than their boiling points suggest, because they are strongly hydrogen-bonded (group III in Table 9.2). 

Table 13.4 Liquid Hydrogen Bubble Point Pressure Computed at the Normal Boiling Point for Candidate Screens for the Fuel Depot...

Pure hydrogen peroxide is a colourless, viscous liquid, m.p. 272.5 K, density l,4gcm . On heating at atmospheric pressure it decomposes before the boiling point is reached and a sudden increase of temperature may produce explosive decomposition, since the decomposition reaction is strongly exothermic ... 

Some ortho substituted phenols such as o mtrophenol have significantly lower boiling points than those of the meta and para isomers This is because the intramolec ular hydrogen bond that forms between the hydroxyl group and the substituent partially compensates for the energy required to go from the liquid state to the vapor... 

Azeotropic distillation. In some cases two or more liquids form constant-boiling mixtures, or azeotropes. Azeotropic mixtures are most likely to be found with components which readily form hydrogen bonds or are otherwise highly associated, especially when the components are dissimilar, for example an alcohol and an aromatic hydrocarbon, but have similar boiling points. 

Hydrogen cyanide (prussic acid) is a liquid with a boiling point of 26°C. Its vapour is flammable and extremely toxic. The effects of acute exposure are given in Table 5.34. This material is a basic building block for the manufacture of a range of chemical products such as sodium, iron or potassium cyanide, methyl methacrylate, adiponitrile, triazines, chelates. 

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