Hydrogen Cyanide Anhydrous

round-bottom flask, set up in a good hood (Note x), is fitted with a three-holed rubber stopper that holds two 2 50-cc, separatory funnels, A and B (Fig. 1). A small funnel, F. (about 3-4 cm. in diameter) is suspended directly under the outlets of the two separatory funnels and is attached to the 

One of the separatory funnels is filled with 1 1. of sulfuric acid prepared by the careful addition of 392 g. (4 moles) (213 cc.) of concentrated sulfuric acid to 213 cc. of water. The other separatory funnel is filled with a solution of 203 g. of commercial sodium cyanide (about 96 per cent) (4 moles) dissolved in sufficient water to make 500 cc. of solution. Evolution of hydrogen cyanide takes place on the simultaneous addition of the two solutions. Practically all of the reaction occurs in the funnel, F, and the sodium bisulfate solution continuously drains into the flask so that fresh solutions are always present. The solution in the funnel remains clear as long as sufficient sulfuric acid is present. An excess of sodium cyanide colors the solution yellow and leads to the formation of a muddy brown precipitate. By adjusting the flow of solutions the rate of evolution is easily controlled, and the preparation requires no attention beyond that involved in the occasional replenishment of the solutions in the separatory funnels. The last part of the hydrogen cyanide can be driven from the apparatus by boiling the bisulfate solution for a few minutes. The yield of acid melting at — r5° to — r4.5° is roo-ro5 g. (93-97 per cent of the theoretical amount) (Notes 3 and 4). 

Gattermann 1 recommends that the operator smoke during the preparation, for he found that a trace of hydrogen cyanide is 

It is essential that the coil be cooled with ice only. A freezing mixture causes solidification of the hydrogen cyanide with consequent clogging of the apparatus. 

The hydrogen cyanide is best kept over anhydrous calcium chloride. In this way it remains clear and water-white for months otherwise, it soon becomes yellow, owing to the formation of azulmic acid. 

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Hydrogen cyanide (anhydrous), 15, 89 Hydrogen peroxide, 13, 94 16, 31 16, 4 Hydrogen sulfide, 16, 81 Hydrolysis... 

HYDROGEN CYANAMIDE see COH500 HYDROGEN CYANIDE see HHSOOO HYDROGEN CYANIDE (ACGIH,OSHA) see HHSOOO HYDROGEN CYANIDE, anhydrous, stabilized (UN 1051) (DOT) see HHSOOO... 

Ziegler, K. 1941. Hydrogen cyanide (anhydrous). Organic Syntheses, 1 314. 

HYDROGEN CYANIDE, ANHYDROUS (74-90-8) Can be self-reactive, forming an explosive mixture with air (flash point 0°F/— 18°C). Unless inhibited, material stored more than 90 days may be hazardous. Heat above 356°F/180°C or contact with alkalis or amines can cause explosive polymerization. Violent reaction with strong oxidizers, acetaldehyde. Solutions containing more than 2-5% water are less stable than dry material. Acid solutions react with ammonia, ferric oxide, halogens, ozone. Attacks some plastics, rubber, and coatings. Water solutions attack carbon steels at room temperatures and stainless steels (especially if stabilized with sulfuric acid) above 176°F/80°C. 

Hydrogen Cyanide, anhydrous, stabilized 1051 13 than 5% available chlorine Hypochlorites, inorganic, n.o.s. 3212 35... 

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