Silver chloride sols

In this preliminary study, we have investigated the coagulation rate of silver chloride sols in microemulsion media. The results are intimately related to structural properties of the microemulsions. 

The total surface, however, can be decreased by rccrystallization, a phenomenon which of course is more pronounced the higher the solubility of the colloid So with metal sols this form of coarsening is very weak but in silver-chloride sols it is so pronounced that AgCI sols (solubility product 10 ) caiihot be preserved for a very long time. 

The redispersion of a sol which has been precipitated by the addition of an electrolyte may also occasionally be effected by the removal of the precipitating agent through washing thus certain precipitates such as silver chloride, zinc sulphide and copper ferro-cyanide are readily redispersed in water where the precipitating salts are removed by thorough agitation and filtration. 

K bromide solns v si sol in w. It occurs in nature as the mineral born silver and is formed when a soln of a sol chloride is added to a soln of a Ag salt. Silver chloride in contact with metallic Na or K is exploded by percussion (Ref 3). Its ammoniacal soln absorbs acetylene, forming Silver Acetylide Chloride complexes which are expl (See Vol 1, p A80 l. Silver chloride is used in medicine as an antiseptic nerve sedative, in the manuf of pure Ag Ag salts, and in photography photometry(Refs... 

C16H15N9 mw 333.40 N 37.82% white ndles (from ethanol) mp 184°. V sol in Na bicarbonate soln sol in ethanol and benz si sol in eth. Prepn is by reacting di-p-toluylhydrazide chloride with an ale soln of Na azide for 20 hrs at RT. The Na salt of the compd, when reacted with a hot aq soln of Ag nitrate, forms the expl Silver Salt. Sol in dll aq ammonia insol in ethanol and w. The salt> explds mildly when heated rapidly on a porcelain spatula... 

White, tetragonal crystals, dj 4.430. mp 230°, dec 270" forming silver chloride and oxygen. Solubility in water (g/100 ml) 10 0D 20 (27 ) 50 (80 ). Slightly sol in ale. Darkens upon exposure to light due to slow decompn. Keep away from tight, organic vapors and oxidizable substances. 

White or grayish, odorless powder stable in dry air darkens on exposure to light dec at 320. Poisonousl d 3.95. Insol in water, alcohol, or dil acids sol in alkali cyanides and in boiling coned nitric acid converted by dil HO into hydrocyanic acid and silver chloride sparingly sol in dil, more in coned ammonia. Protect from light. 

Fig. II.9. 3a-b (a) Schematic description of the silver electrode as an example for an electrode of the first kind. Sol indicates the solution, (b) Schematic description of the silver-silver chloride electrode as an example for an electrode of the second kind. Sol indicates the solution and s indicates the solid salt...

Sols are dispersions of small solid particles in a liquid. The particles may be mactomol-ecules or maybe clusters of small molecules. Lyophobic sols are those in which there is no nity between the dispersed phase and the liquid. An example is silver chloride dispersed in water, in such colloids the solid particles have a surface charge, which tends to stop them coming together. Lyophobic sols are inherently unst le and in time the particles aggregate and form a precipitate. Lyophilic sols, on the other hand, are more like true solutions in which the solute molecules are large and have an affinity for the solvent. Starch in water is an example of such a system. Association colloids are systems in which the dispersed phase consists of clusters of molecules that have lyophobic and lyophilic parts. Soap in water is an association colloid (seemicelle). 

Silver Nitride. (Fulminating Silver). Ag3N, mw 337.65, N4.15%, blk-grey powd, mp 25° (start of decompn), d 9.0 lg/cc at 19°. Sol in weak acids, si sol in aq ammonia sol in aq solns of Na chioride and K cyanide. Prepd by treating aq Ag oxide with aq ammonia soln, or by heating coned ammoniacal Ag chloride with solid KOH until evolution of ammonia ceases. The thoroug-ly washed product must be stored under w and, even so, is sensitive to touch (Refs 1—7)... 

Penta-1,3-diyne (Methyldiacetylene). CH3.CiC.CiCH mw 65.10 OB to C02 —294.93% liq mp —4.5 to -38.5° bp 76-77° (explds at atm press), 45° at 140mm d 0.7909 g/cc at 20/4° RI 1.4762 (Ref 3) and 1.4817 (Ref 1). Sol in ethanol and petr with a bp > 180°. Prepn is by reacting monosodium-acetylenide with dichloromethane in liq ammonia at 20 to 40°, followed by treatment with ammonium chloride. The product is stable in the dark at -35° but polymerizes readily at above —20° in the light. Penta-1,3-diyne forms two expl salts Copper penta-1,3-diyne, CuCsH3, dark yel ndls/by reaction with CuCl, explds on shock or by rubbing and Silver penta-1,3-diyne, yel-brn ndls, by reaction with aq silver nitrate in ammonium hydroxide, a v expl compd Refs 1) Beil 1, [247], 1057 <1117)... 

Ethyl-3,3-dinitrobenzoatef ndls (from ale), sp gr 1.295 at 111°, mp 91—2°, bp — not given insol in w si sol in ale. It may be prepd from the silver salt of the acid and ethyi iodide, from the acid and ale HC1 from the acid chloride in benzene from tbe chloride and ether with zinc chloride... 

Lc yel crysts, mp 240° with decompn starts to blacken ca 200° sol in ben acet in sol in ligroin. Was prepd by treating silver salt of hexanitrodi phenyl amine with acetyl chloride. No refs to its expl props... 

This rearrangement must occur by heterolytic cleavage of the carbon-chlorine bond in 19 to yield the intermediate cation 6+, which is then attacked by the nucleophilic chloride at one of the partially positively charged cyclopropyl groups. With the less nudeophilic tetrafluoroborate counterion, generated by treating 19 with silver tetrafluoroborate under sol-... 

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