Metal spatulas

Step 3. The non-steam-volatile compounds. The alkaline solution (82) remaining in the distiUing flask from Step 2 may contain water-soluble, non-volatile acidic, basic or neutral compounds. Add dilute sulphuric acid until the solution is just acid to Congo red, evaporate to dryness, and extract the residual solid with boiling absolute ethyl alcohol extraction is complete when the undissolved salt exhibits no sign of charring when heated on a metal spatula in the Bunsen flame. Evaporate the alcoholic solution to dryness and identify the residue. 

Its positive enthalpy of formation makes it likely to be highly unstable thermodynamically. Indeed, its explosive decomposition caused numerous accidents. So, 5 g of this compound touched with a metal spatula causes ite detonation. Its crystallisation can also cause its detonation and there should be... 

A mixture of solid silver nitrate and ethanol was handled with a metallic spatula. The mixture detonated as soon as it came into contact with the spatula. This detonation could be explained by the accidental formation of silver fulminate. However, witnesses noticed the smell of ethyl nitrate after the accident. 

An ethereal solution of some 100 g of the crude nitrile was allowed to spontaneously evaporate and crystallise. The crystalline slurry so produced exploded violently without warning. Previously such material had been found not to be shock-sensitive to hammer blows, but dry recrystallised material was very shock-sensitive. Traces of free hydrogen azide could have been present, and a metal spatula had been used to stir the slurry, so metal azides could have been formed. See Other CYANO COMPOUNDS, ORGANIC AZIDES... 

Though the preparative method is suitable for large scale synthesis, the product must be handled with care. On rapid heating, the internal diazonium salt decomposes violently at 155-160°C accompanied by a sharp sound. The dried powder should not be scratched with a metal spatula or ground finely. 

The monohydrate explodes at 109 -110° C during slow heating [ 1 ]. The solid complex exploded when manipulated on a glass sinter with a metal spatula [1]. Preparation on small scale and use of plastic equipment is recommended [2],... 

Small explosions were observed on scratching the crystals with a metal spatula. 

Pyrophoric in air, deflagrates under nitrogen on scratching with a metal spatula, and reacts explosively with alcohols or water. 

The solution, obtained by conventional diazotisation of the amine, contained some solid which was removed by filtration on a glass lfit. The solid, thought to be precipitated diazonium salt (possibly an internal salt), exploded violently when disturbed with a metal spatula. 

A sample prepared by an established method and stored overnight at 2°C exploded when disturbed with a metal spatula. 

The complex sometimes explodes when scraped against a glass frit with a metal spatula. 

A small sample exploded when scraped with a metal spatula on a glass frit. 

Materials for a batch of ammonium perchlorate castable propellant were charged into a mechanical mixer. A metal spatula was left in accidentally, and the contents ignited when the mixer was started, owing to local friction caused by the spatula. A tool-listing safety procedure was instituted [1]. The literature on the kinetics of thermal decomposition has been reviewed critically [2],... 

The anhydrous salt was stable to 300°C or to impact of a steel hammer, but a mild explosion occurred when a grease-containing sample was disturbed with a metal spatula. 

The dry material explodes on slight compression, or on heating at 130-230°C. Contact with bromine, chlorine or a little fuming hydrochloric acid also causes explosion [1], Explosions when manipulated with a metal spatula are reported [2],... 

In all microscopic methods, sample preparation is key. Powder particles are normally dispersed in a mounting medium on a glass slide. Allen [7] has recommended that the particles not be mixed using glass rods or metal spatulas, as this may lead to fracturing a small camel-hair brush is preferable. A variety of mounting fluids with different viscosities and refractive indices are available a more viscous fluid may be preferred to minimize Brownian motion of the particles. Care must be taken, however, that the refractive indices of sample and fluid do not coincide, as this will make the particles invisible. Selection of the appropriate mounting medium will also depend on the solubility of the analyte [9]. After the sample is well dispersed in the fluid, a cover slip is placed on top... 

The band is outlined with pencil and then scraped with a metal spatula (Fig. 13.21) and collected in a beaker. This step is repeated for all 12 plates to increase the concentration of the impurity. 

While still moist the bulk of the material is transferred to a test tube even in the moist condition pressing with a metal spatula or other hard object is to be avoided. Then 2 c.c. of concentrated hydrochloric acid are poured into the test tube, when the odour of free fulminic acid can be perceived. This odour so closely resembles that of hydrocyanic acid as to make confusion possible. After half an hour the contents of the test tube are heated for a short time in the boiling water bath, 4 c.c. of water are added, silver chloride is removed by filtration, and the filtrate is evaporated to dryness on... 

Draw dividing lines 0.5 to 1.0 mm broad on the surface of the layer with a narrow-metal spatula,... 

Boil the liquid in a pan on the stove until most of the water is gone. Transfer it to an iron skillet and heat until all of the water has evaporated. Stir with a metal spatula while this occurs to obtain a good grade of powdered ferrocyanide. 

Hydrogen tetrachloroaurate(l —), H[AuCl4]nH20, or brown gold chloride, was obtained from Johnson Matthey this compound is quite hygroscopic, and may plate out gold on metal spatulas. Triphenylphosphine was obtained from BDH Chemicals. 

A magnetic stirring bar is used for initial stirring. A thick slurry develops and when magnetic stirring becomes impossible, the mixture is stirred with a metal spatula for about 1 min. 

NAGu consists of wh monocl crysts(ftom w), apparent d 0.22 g/cc, mp 184°(decomp) expl ca 190°. When heated on a metallic spatula near a flame, each particle of NAGu expl as it is ignited by the flame. It may be ground in a mortar without producing an expln. One of the methods for its prepn is the interaction of nitroguanidine with hydrazine sulfate in ammonia. This and other methods are described in Refs 1,2,3,4a,6,... 

Solvent system, petroleum ether-dioxane-acetone (70 30 10, v/v/v) Chromatography chamber Metal spatula or clean razor blade... 

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