Water hydration and

The protein fraction showed low nitrogen solubility and rather low water hydration and oil absorption values relative to those of the proteinates but oil emulsification was quite high. Refined legume fiber had a water hydration capacity of over 20 g/g product. 

This azide, prepared by adding a solution of n-butyl bromide to a slurry of of sodium azide in water, cleaves ketones of the type ArCOCHjR in benzene or nitrobenzene at 70-90° in the presence of a catalytic amount of sulfuric acid to two carbonyl components. Acetophenone gives benzaldehyde (80%) and formaldehyde (83%) propiophenone gives benzaldehyde and acetaldehyde. The reaction is interpreted as involving combination of the azide with the coiyugate acid of the ketone, release of nitrogen from the diazonium cation with elimination of water, hydration, and cleavage. 

In the presence of water, hydrated and anhydrous crystals can be considered as being in equilibrium ... 

Water hydration and counter-ion solvation of biological macro molecules considerably alter the translational and rotational dynamics ofbiological macromolecules. The effect can be correlated with a number of different solution properties of a given biological macromolecule such as the hydrated volume Vh- The term Vh is given by... 

Theoretical calculations of the H NMR spectra of phosphonic and phosphoric acids in different states (without water, hydrated, and deprotonated) in CClj medium give relatively broad distribution functions (Figure 1.128) because a portion of protons does not participate in the hydrogen... 

The metal ions are found in aqueous solution surrounded by water molecules as aqua complexes (or aqua acids). The hydrated ions can undergo stepwise hydrolysis with delivery of one or more H+ to the bulk solvent. This process occurs due the attraction of the metal ion to the electron cloud of its water hydration, and the weakening of the OH bond in the H2O molecule. The process can be represented by the reaction. 

Several works have shown that, in general, pyranoanthocyanins exhibit a higher color intensity and stability up to pH 6 and higher resistance to bisulfite bleaching than anthocyanins. The substitution at the carbon 4 of the pyranic ring C protects the chromophore group from the nucleophilic attack of water (hydration) and bisulfite anion (Bakker ... 

Equation (1) is readily recast in a form that is suitable for calculating the conditions for hydrate stability. Note that for a true three-phase equilibrium between water, hydrate and guest phases, the chemical potential of each individual species must be the same in all three phases. Thus must equal the chemical potential of water in its stable pure phased and we have that... 

Zn " solutions by, e.g., NaOH. Occurs hydrated and loses water on heating. Dissolves in acids and in excess alkali (to give zincates). Used as rubber filler and as an absorbent in surgical dressings. 

Under certain conditions of temperature and pressure, and in the presence of free water, hydrocarbon gases can form hydrates, which are a solid formed by the combination of water molecules and the methane, ethane, propane or butane. Hydrates look like compacted snow, and can form blockages in pipelines and other vessels. Process engineers use correlation techniques and process simulation to predict the possibility of hydrate formation, and prevent its formation by either drying the gas or adding a chemical (such as tri-ethylene glycol), or a combination of both. This is further discussed in SectionlO.1. 

Israelaohvlll J N 1996 Role of hydration and water struoture In blologloal and oolloldal Interaotlons Nature 379 219-25... 

The majority of practical micellar systems of Tionnal micelles use water as tire main solvent. Reverse micelles use water immiscible organic solvents, altlrough tire cores of reverse micelles are usually hydrated and may contain considerable quantities of water. Polar solvents such as glycerol, etlrylene glycol, fonnamide and hydrazine are now being used instead of water to support regular micelles [10]. Critical fluids such as critical carbon dioxide are... 

Unlike solid leadflF) chloride which is ionic and which dissolves in water to form hydrated and CP ions, lead(TV) chloride is an essentially covalent volatile compound which is violently hydrolysed by water. 

Cobalt II) halides can be obtained by direct combination of the elements, or by dehydration of their hydrates. Anhydrous cobalt(II) chloride is blue, and the solid contains octahedrally-coordinated cobalt the hydrated salt C0CI2. bHjO is pink, with each cobalt surrounded by four water molecules and two chloride ions in a distorted octahedron. 

Taking into account the hydration shell of the NA and the possibility of the water content changing we are forced to consider the water -I- nucleic acid as an open system. In the present study a phenomenological model taking into account the interdependence of hydration and the NA conformation transition processes is offered. In accordance with the algorithm described above we consider two types of the basic processes in the system and thus two time intervals the water adsorption and the conformational transitions of the NA, times of the conformational transitions being much more greater... 

Place 80 g, of hydroxylamine sulphate (or 68-5 g. of the hydrochloride), 25 g. of hydrated sodium acetate, and 100 ml. of water in a 500 ml. flask fitted with a stirrer and a reflux water-condenser, and heat the stirred solution to 55-60°. Run in 35 g (42 nil,) of -hexyl methyl ketone, and continue the heating and vigorous stirring for ij hours. (The mixture can conveniently be set aside overnight after this stage.) Extract the oily oxime from the cold mixture twice with ether. Wash the united ethereal extract once with a small quantity of water, and dry it with sodium sulphate. Then distil off the ether from the filtered extract, preferably using a distillation flask of type shown in Fig. 41 (p. 65) and of ca, 50 ml, capacity, the extract being run in as fast as the ether distils, and then fractionally distil the oxime at water-pump pressure. Collect the liquid ketoxime, b.p. 110-111713 mm. Yield, 30-32 g. 

Pinacolone. In a 500 ml. round-bottomed flask carrying a dropping funnel and a connection to a condenser set for distillation, place 50 g. of pinacol hydrate and 130 ml. of QN sulphuric acid. Distil the mixture until the upper layer of the distillate no longer increases in volume (15-20 minutes). Separate the pinacolone layer from the water and return the latter to the reaction flask. Then add 12 ml. of concentrated sulphuric acid to the water, followed by a second 50 g. portion of pinacol hydrate. Repeat the distillation. Repeat the process twice more until 200 g. of pinacol hydrate have been used. 

Fit a 1500 ml. bolt-head flask with a reflux condenser and a thermometer. Place a solution of 125 g. of chloral hydrate in 225 ml. of warm water (50-60°) in the flask, add successively 77 g. of precipitated calcium carbonate, 1 ml. of amyl alcohol (to decrease the amount of frothing), and a solution of 5 g. of commercial sodium cyanide in 12 ml. of water. An exothermic reaction occurs. Heat the warm reaction mixture with a small flame so that it reaches 75° in about 10 minutes and then remove the flame. The temperature will continue to rise to 80-85° during 5-10 minutes and then falls at this point heat the mixture to boiling and reflux for 20 minutes. Cool the mixture in ice to 0-5°, acidify with 107-5 ml. of concentrated hydrochloric acid. Extract the acid with five 50 ml. portions of ether. Dry the combined ethereal extracts with 10 g. of anhydrous sodium or magnesium sulphate, remove the ether on a water bath, and distil the residue under reduced pressure using a Claiseii flask with fractionating side arm. Collect the dichloroacetic acid at 105-107°/26 mm. The yield is 85 g. 

Place 36 -0 g. of redistilled acetophenone, b.p. 201° (Section IV,136), 300 ml. of diethylene glycol, 30 ml. of 90 per cent, hydrazine hydrate and 40 g. of potassium hydroxide pellets in a 500 ml. Claisen flask provided with a reflux condenser and a thermometer dipping into the liquid (compare Fig. Ill, 31, 1). Warm the mixture on a boiling water bath until most of the potassium hydroxide has dissolved and then reflux (free flame) for one hour. Arrange the apparatus for distillation and distil until the temperature in the liquid rises to 175° (1) keep the distillate (ca. 50 ml.). Replace the reflux condenser in the flask and continue the refluxing for 3 hours. 

Benzylatnine. Warm an alcoholic suspension of 118-5 g. of finely-powdered benzyl phthalimide with 25 g. of 100 per cent, hydrazine hydrate (CAUTION corrosive liquid) a white, gelatinous precipitate is produced rapidly. Decompose the latter (when its formation appears complete) by heating with excess of hydrochloric acid on a steam bath. Collect the phthalyl hydrazide which separates by suction filtration, and wash it with a little water. Concentrate the filtrate by distillation to remove alcohol, cool, filter from the small amount of precipitated phthalyl hydrazide, render alkaline with excess of sodium hydroxide solution, and extract the liberated benzylamine with ether. Dry the ethereal solution with potassium hydroxide pellets, remove the solvent (compare Fig. //, 13, 4) on a water bath and finally distil the residue. Collect the benzylamine at 185-187° the 3ueld is 50 g. 

Hydrophobic effects include two distinct processes hydrophobic hydration and hydrophobic interaction. Hydrophobic hydration denotes the way in which nonpolar solutes affect the organisation of the water molecules in their immediate vicinity. The hydrophobic interaction describes the tendency of nonpolar molecules or parts thereof to stick together in aqueous media " . A related frequently encountered term is hydrophobicity . This term is essentially not correct since overall attractive interactions exist between water and compounds commonly referred to as... 

Carbonic acid is formed when carbon dioxide reacts with water Hydration of car bon dioxide is far from complete however Almost all the carbon dioxide that is dis solved m water exists as carbon dioxide only 0 3% of it is converted to carbonic acid Carbonic acid is a weak acid and ionizes to a small extent to bicarbonate ion... 

After heating to 50 °C in a water bath, the sample was cooled to below room temperature and filtered. The residue was washed with two 5-mL portions of CCI4, and the combined filtrates were collected in a 25-mL volumetric flask. After adding 2.00 mL of the internal standard solution, the contents of the flask were diluted to volume with CCI4. Analysis of an approximately 2- tL sample gave LfD signals of f3.5 for the terpene hydrate and 24.9 for the camphor. Report the %w/w camphor in the analgesic ointment. 

Protein molecules extracted from Escherichia coli ribosomes were examined by viscosity, sedimentation, and diffusion experiments for characterization with respect to molecular weight, hydration, and ellipticity. These dataf are examined in this and the following problem. Use Fig. 9.4a to estimate the axial ratio of the molecules, assuming a solvation of 0.26 g water (g protein)"V At 20°C, [r ] = 27.7 cm g" and P2 = 1.36 for aqueous solutions of this polymer. 

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