Monoclinic system

Why is there no biclinic system in which a 7 b 7 c and a = 90°, y f 90° This is because it produces no different symmetry than the triclinic system. 

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Crystals of the dihydrate belong to the monoclinic system and have lattice parameters a = 659 pm, b = 1020 pm, and c = 651 pm. The anhydrous crystal belongs to the cubic system, a = 596 pm. Other physical properties of the anhydrous salt are Hsted iu Table 1. The anhydrous salt is hygroscopic but not dehquescent. 

Gypsum crystals have an SG of 2.32, are colourless and belong to the monoclinic system. Figure 2 shows photographs of industrial and laboratory gypsum crystals. The crystals are elongated and can range up to 40 pm in size. 

SOAz (II) This second crystalline form adopts the monoclinic system, systematic reflection absences indicating P2j/c as the space group. The volume of the cell is twice that of SOAz (I), indicating that the two crystallographically independent... 

The compound crystallizes in the monoclinic system with unit-cell dimensions of a = 6.64 A b = 8.58 A c = 4.54 A (3 = 102.8°. These data agree well with those reported by Lukaszewicz.4 Manganese diphosphate can be identified according the following powder diffraction lines ... 

The crystal descriptions become increasingly more complex as we move to the monoclinic system. Here all lattice parameters are different, and only two of the interaxial angles are orthogonal. The third angle is not 90°. There are two types of monoclinic space lattices simple monoclinic and base-centered monoclinic. The triclinic crystal, of which there is only one type, has three different lattice parameters, and none of its interaxial angles are orthogonal, though they are all equal. 

Hexammino-iridium Chloride, [Ir(NH3)e]Cl3, is prepared by heating chloro-pentammino-iridium chloride, [Ir(NH3)5Cl]CI2, with 25 per cent, aqueous ammonia in a sealed tube to 140° C. The crude product so obtained is evaporated with hydrochloric acid, the residue dissolved in water, and precipitated by means of sodium pyrophosphate. From this the nitrate is formed by treating with dilute hydrochloric and nitric acids, and finally the nitrate is decomposed by repeated evaporation to dryness with concentrated hydrochloric acid. The residue is then treated with ice-cold hydrochloric acid, when the chloride is precipitated. It crystallises in large six-sided colourless prisms belonging to the monoclinic system, and is soluble in water.1... 

J. C. G. de Marignac showed that the crystals are trimorphous, for they exist in three different forms (i) Thick plates belonging to the rhombic system—Pig. 16 (ii) twinned pyramids belong to the monoclinic system—Fig. 17 and (iii) thick plates also belonging to the monoclinic system—Fig. 18. Aq. soln. redden litmus,... 

Anhydrous lithium carbonate forms a voluminous white powder both A. Arfvedson1 and L. Kralowansky obtained the salt in a crystalline form, and by evaporating a soln. sat. at 15°, F. C. Fliickiger obtained long prisms which, according to E. Mallard, belong to the monoclinic system, with axial ratios orb c=l 672 1 1244, and /J=114° 25. The fused salt also furnishes a mass... 

The crystals of the anhydrous salt are short prisms belonging to the monoclinic system. T. Fleitmann found that 100 parts of cold or hot water dissolve 87 parts of the salt. A. Glatzel found that the salt is easily soluble in acids, and when the acidified soln. are boiled orthophosphoric acid is formed. The aq. soln. has an alkaline reaction, and when boiled it beoomes acid, and contains no more... 

Its crystals belong to the monoclinic system. The product used in industrial practice should be crystalline in form and be easily pourable into a mould for compression. According to Davis [21] a product with mixed, i.e. relatively large and small crystals (Fig. 5), is best suited for this purpose. 

The same type of unit cell is appropriate for class m, the a and c axes lying in the. plane of symmetry, with the 6 axis normal to this plane. It is equally appropriate for class 2jm. The three classes 2, m, and 2/m constitute the monoclinic system (Pig. 33). 

Fig. 33. Monoclinic system. (See also Fig. 26.) a. Unit aell type. 6. Left- and right-handed tartaric acid. ClasB 2. c. 2,4,6 Tribromobenzonitrile. Class m. d, p-Dinitro-benzene. Class 2/m. e. (CH3COO)8Pb.3HaO. Class 2/m.

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