Six-sided crystal

Chloroform and water at 0°C form six-sided crystals of a hydrate, CHCl I8H2O [67922-19-41which decompose at 1.6°C. Chloroform does not decompose appreciably when in prolonged contact with water at ordinary temperature and in the absence of air. However, on prolonged heating with water at 225°C, decomposition to formic acid, carbon monoxide, and hydrogen chloride occurs. A similar hydrolysis takes place when chloroform is decomposed at elevated temperature by potassium hydroxide. 

When metallic sodium and diphenylsilicon diehloride (rather more of the metal than calculated for the proportion 2Na SiPh2Cl2) in 3 to 10 volumes of toluene or xylene are heated, reaction occurs as the sodium melts. In some cases the metal was added in small quantities, and in others the diehloride was added slowly to the metal, but either process gives the same result. From the solution, six-sided crystals separate (A), and the solution is cooled and filtered, the dark blue residue being extracted witli boiling toluene. This extract deposits crystals of (A), and from the mother-liquors a second crystalline substance (C) is obtained. The dark l >lue powder, treated with alcohol-acetic acid, then with water, gives a small quantity of flocculent substance (D). 

One of the main uses of these wet cells is to investigate surface electrochemistry [94, 95]. In these experiments, a single-crystal surface is prepared by UFIV teclmiqiies and then transferred into an electrochemical cell. An electrochemical reaction is then run and characterized using cyclic voltaimnetry, with the sample itself being one of the electrodes. In order to be sure that the electrochemical measurements all involved the same crystal face, for some experiments a single-crystal cube was actually oriented and polished on all six sides Following surface modification by electrochemistry, the sample is returned to UFIV for... 

Wash with Et20 and crystallise from EtOH (six sided plates). Hygroscopic and forms crystals with one mol H2O. [Justus Liebigs Ann Chem 229 320 1885-, Chem Ber 83 291 1950.]... 

Figure 4.5 shows a conventional unit cell of an fee crystal. It consists of atoms at the eight edges of a cube and at the centers of the six sides. The length a of the side of the cube is the lattice constant-, for our present purpose we may assume that it is unity. The lattice of an infinite, perfect solid is obtained by repeating this cubic cell periodically in all three directions of space. 

Figure 4.5 Conventional unit cell of a face-centered cubic crystal. The lattice contains the points at the corners of the cube and the points at the centers of the six sides.

Quartz is found in several forms in all three major kinds of rocks—igneous, metamorphic, and sedimentary. It is one of the hardest minerals known. Geologist often divides quartz into two main groupings—course crystalline and cryptocrystalline quartz. Course crystalline quartz includes six-sided quartz crystals and massive granular clumps. Some colored varieties of coarse crystalline quartz crystals, amethyst and citrine, are cut into gem stones. 

As Table 8 shows, the analogous ratios CsF/RbF and BaO/SrO differ little from each other. Those for /z agree within 1/2%, while for ter in the crystals, in which the six-sided polarization exerts a relatively small influence on r, these ratios agree within 1%. The corresponding ratios for tm in the molecules differ 2.5%, the distance in BaO, for which P = 0.426 has the smallest value, being shortened most by the one-sided polarization. 

Oxalato-tetrammino-cobaltic Chloride, [Co(NH3)4(C204)]C1, is prepared by dissolving chloro-aquo-tetrammino-eobaltic chloride in an aqueous solution of oxalic acid and heating the mixture for some time. The oxalato-compound gradually crystallises from the warm solution, and the crystals are collected and washed on the filter with alcohol until the filtrate is free from chlorine and from oxalic acid. It crystallises in carmine-red six-sided plates if dissolved in concentrated sulphuric acid and concentrated hydrochloric acid is added to the liquid, it is transformed into dichloro-tetrammino-cobaltic chloride. Sodium nitrite and acetic acid convert it into dinitro-tetrammino-cobaltic chloride.1... 

Sulphate of Potassa—Variolated Tartar f Sal-polycrest.—This salt is most conveniently prepared by neutralizing with carbonate of potassa the bisulphate of this base, as obtained in the preparation of nitric acid, or by expelling the excess of sulphuric acid by heating the bisulphate to redness. It may also be formed synthetically by Haturattog carbonate of potassa with diluted, sulphuric acid, and evaporating the liquor that crystals may be formed. Sulphate of potassa—KO, SOg—is especially distinguished by its hardness. Tho form of the crystal fa that of a six-sided prism, These crystals contain no water of combination but when heated,... 

Constitution and Properties.—Quinin is one of the more powerful organic alkalies. It generally appears, whan pure, as an amorphous, resinous mass, of a dull whits color. Its formula is—CM Hw Na Ot -(- 6 aq. It may also be obtained in six-sided prismatic crystals, which ore a hydrate, containing six equivalents, or 10 5 per cent, of water, which are lost on fusion. 

The six-sided geometry of ice crystals gives rise to the six-sided structure of snowflakes. 

Diffraction patterns can be described in terms of three-dimensional arrays called lattice points.33 The simplest array of points from which a crystal can be created is called a unit cell. In two dimensions, unit cells may be compared to tiles on a floor. A unit cell will have one of seven basic shapes (the seven crystal systems), all constructed from parallelepipeds with six sides in parallel pairs. They are defined ac-... 

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