Water in crystals

The water in crystals may. however, be present in other than definite lattice positions. For example, the water molecules may be found in holes in the lattices, oi they may occupy random positions in ihe lattices. The latter situation is often found in ion exchange resins where loss of water, up to a certain point, dties not materially change the lattice structure. 

Mercury fulminate has a specific gravity of 4.45, but a mass of the crystals when merely shaken down has an apparent density (gravimetric density) of about 1.75. In detonators the material is usually compressed to a density of about 2.5, but densities as high as 4.0 have been obtained by vigorous compression. Mercury fulminate crystallizes from water in crystals which contain y.H20, from alcohol in crystals which arc anhydrous. One liter of water at 12° dissolves 0.71 gram, at 49° 1.74 grams, and at 100° 7.7 grams. 

The crude molecular image seen in the F0 map, which is obtained from the original indexed intensity data (IFobsI) and the first phase estimates (a calc), serves now as a model of the desired structure. A crude electron density function is devised to describe the unit-cell contents as well as they can be observed in the first map. Then the function is modified to make it more realistic in the light of known properties of proteins and water in crystals. This process is called, depending on the exact details of procedure, density modification, solvent leveling, or solvent flattening. 

What reasons have you for believing that the water in crystal hydrates is in chemical combination with the salt ... 

Kainuma, K., and French, D. 1972. Naegeli amylodextrin and its relationships to starch granule structure. II. Role of water in crystallization of B-starch. Biopolymers 11, 2241. 

Hydrazine can occupy the space commonly occupied by water in crystallization. These compounds are sometimes called hydrazinates in analogy to hydrates. This addition is reversible. Hydrazinium salts and their hydrazine adducts can be used as gas generators, for example, (N2H5 )2(N2H4)2C2Nio as they release huge amounts of gas upon decomposition. ... 

Dunitz JD. The Entropic Cost of Bound Water in Crystals and... 

Sulphanilic acid is difficultly soluble in cold water, and crystallizes from hot water in crystals which contain two molecules of water and effioresce quickly. 

Dunitz, J. (1994) The entropic cost of bound water in crystals and biomolecules. Science, 264, 670... 

Our perspective on the internal pore structure was notably qualified by comparative studies of the water distribution in the above considered CrAPO-5 crystals and in SAP0-5, as another representative of the AFI family [78]. Figure 40 displays the equilibrium distribution of water in crystals of CrAPO-5 (left) and SAPO-5 (right) in a water atmosphere of 1 mbar (top and bottom) and of 20 mbar (middle). The water distribution at 1 mbar has been considered after both adsorption from Ombar (top) and desorption from 20 mbar, i.e., from the situation shown in the middle of the figure (bottom). We note the following important results ... 

Karl Fischer titrations are frequently used for the analysis of water content in such samples as food materials, pharmaceuticals, and solvents used in industrial applications, or for the determination of hydration water in crystals. Dedicated units are commercially available and many automatic titra-tors or pH meters feature a connector for current biased voltage measurements labeled Karl-Fischer or simply KF . 

The hydrosphere consists mainly of oceanic and terrestrial freshwater in the liquid phase. Compared to terrestrial water enviromnents, such as rivers, lakes and ground water, the chemical composition of the oceans is relatively constant. The amount of water contained in the soil, in minerals and rocks (fluid inclusions, adsorbed surface water, water in crystals etc.), water component of organisms, and water vapor in the atmosphere, all of which are found near the earth s surface environment, is minor. 

Salt Water in Crystal Lattice Primary Water Layer Bulk Water Water in Crystal Lattice Primary Water Layer Bulk Water... 

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