Hygroscopic substances

A) Rectified ethanol, contains 95-6% ethanol. 4-4 ., water. Care in using it with hygroscopic substances. 

The use of paraffin in the expl industry is extensive, not only as a moisture protecting agent, but as a desensitizer. Paraffin can be incorporated either directly with ingredients of expl compns (at a temp above its mp), or one or more ingredients can be coated separately with molten paraffin and then mixed. When hygroscopic substances, such as AN, Na nitrate, etc, are coated in such a manner, they are rendered less hygroscopic, and, when the same procedure is applied to sensitive compds or expls (K chlorate, RDX, PETN, etc) their sensitivity can be markedly reduced... 

The typical cream, a soft, emulsified mass of solidified particles in an aqueous, micelle-rich medium, does not form a water-impermeable (occlusive) film on the skin. Nevertheless, creams contain lipids and other moisturizers that replace substances lost from the skin in the course of everyday living. Creams thus make good emollients because, by replenishing lipids and in some instances also polar, hygroscopic substances,... 

Weigh the substance in a small open platinum boat weigh hygroscopic substances in a small weighing bottle. 

Hygroscopic. Substances capable of adsorbing moisture from the air, such as silica gel and calcium carbide. 

Under indoor conditions, in the same way than outdoors, it is necessary the presence of surface humidity for corrosion to occur due to the electrochemical nature of the atmospheric corrosion process however, in indoor conditions there are no precipitations and the presence of surface water depends mainly on water content in the air and changes in temperature on the surface, as well as the presence of hygroscopic substances on the metallic surface. 

Prepd by one-stage nitration of lysol. It has been proposed for use as an additive to reduce the mp of other expls such as PA. It is also suitable for the manuf of plastic expls, and for coating hygroscopic substances such as Na nitrate, to protect against moisture (Refs 1 2) Refs 1) E. Raynaud, FrP 449785 (1912) ... 

Humectants hygroscopic substances incorporated in a product to promote retention of moisture, including moisture retention agents and antidusting agents. 

The final product must have a known, stable composition. A hygroscopic substance is one that picks up water from the air and is therefore difficult to weigh accurately. Many precipitates contain a variable quantity of water and must be dried under conditions that give a known (possibly zero) stoichiometry of H20. 

The action of hydrogen sulphide at high temperatures on sodium pyrovanadate gives rise to sodium pentathiopyrovanadate, Na4V2Ss02, which is a hygroscopic substance very similar in its colour and lustre to potassium permanganate. 

The crude, somewhat hygroscopic, substance may be further purified by extraction with 200ml of carbon disulfide for about 24 hours in a Soxhlet apparatus on the steam bath. The pure material crystallizes out in the receiver as very pale-ydlow crystals which are dried in vacuo. 

Rcell. OCH2.COONa colorless, odorless and tasteless, non-toxic, hygroscopic substance, easily dispersible in hot or cold w, but insol in most organic solvents. Can be prepd by treating alkali cellulose with Na chloro-acetate ... 

Alter, H. K. Hygroscopic Substances in Microanalysis. Part I. New Techniques for Drying and Weighing Solids. Mikrochem. 25, 47 (1938). 

Condensation may be induced by substances having a strong chemical affinity for the vapor. Hygroscopic substances such as calcium chloride, sulfur trioxide, etc., rapidly combine with the water vapor and form droplets which have lower vapor pressures upon which more moisture readily condenses. Because they are essentially new substances these droplets possess a permanently lowered vapor pressure. 

Hexanitrosobenzene is a stable, non-hygroscopic substance. It is more sensitive to impact than tetryl. The lead block expansion it gives is larger than that given by tetryl. 

Sodium hypochlorite is a white hygroscopic substance the probable composition of which corresponds to the formula NaOCl. 6 H20. This compound is very unstable and decomposes easily under liberation of oxygen due to this fact the preparation of crystaline salt is very expensive, so for technical purposes it is produced only as an aqueous solution. This can be done either by electrolysis or chemically by gaseous chlorine being introduced into a solution of sodium... 

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