Cylinders hydrogen sulfide

Manufacture. Small cylinders of hydrogen sulfide are readily available for laboratory purposes, but the gas can also be easily synthesized by action of dilute sulfuric or hydrochloric acid on iron sulfide, calcium sulfide [20548-54-3], zinc sulfide [1314-98-3], or sodium hydrosulfide [16721 -80-5]. The reaction usually is mn in a Kipp generator, which regulates the addition of the acid to maintain a steady hydrogen sulfide pressure. Small laboratory quantities of hydrogen sulfide can be easily formed by heating at 280—320°C a mixture of sulfur and a hydrogen-rich, nonvolatile aUphatic substance, eg, paraffin. Gas evolution proceeds more smoothly if asbestos or diatomaceous earth is also present. 

Anon., Lab. Accid. Higher Educ. Item 32, HSE, Barking, 1987 During the reduction of the azide in ethanol with hydrogen sulfide (no regulation other than main cylinder valve) under reflux (with insufficient flow of condenser water), the mixture apparently overheated, then exploded violently. 

Hydrogen sulfide is stable and stored as a compressed, liquefied gas in aluminum or stainless steel cylinders. 

Red Star (British WWI Cylinder Gas) Hydrogen Sulfide (90%) and Carbon Disulfide (10%) Mixture ... 

A bubbler filled with mercury was placed between the gas cylinder and the gas-inlet tube. A good hood should be used throughout the procedure because hydrogen sulfide is toxic in minute concentrations. 

Cylinders of hydrogen sulfide are available from the Mathe-son Company, Inc., East Rutherford, New Jersey. 

A MIXTURE of 326 g. (3.9 moles) of a 36 per cent formaldehyde solution (Note i) and 700 cc. of concentrated hydrochloric acid (sp. gr. 1.18) is placed in a tall glass cylinder (Note 2), and hydrogen sulfide is passed through the solution until no more precipitate is formed. In order to facilitate the process, the accumulated mass of crystals is removed from time to time by filtration. The time required for completion of the reaction varies from twelve to twenty-four hours. A crude 5udd of 176 g. (98 per cent of the theoretical amount) of fine, nearly colorless needles melting at 210-213° is obtained. 

A tall cylindrical vessel insures good contact between the solution and the gas bubbling through it. Hydrogen sulfide from a commercial cylinder was used. 

It is important that the gases (H2S and HCI) be passed very rapidly through the solution. Hydrogen sulfide from a pressurized cylinder can be used instead of a Kipp generator, enabling the gas to be passed at a very rapid rate. However, in this case, it is advisable to use a three-necked, round-bottomed flask fitted with two drying tubes to serve as pressure releases, since there is a pressure buildup as the temperature of the solution rises. 

Carbonyl sulfide is a flammable gas, and may be explosive or spontaneously flammable in air under the right conditions. Vapors may ignite at distant ignition sources and flash back. When exposed to fire, humidity, or strong alkalis, carbonyl sulfide may form the toxic decomposition products carbon monoxide and hydrogen sulfide gas. In the presence of strong oxidizers, carbonyl sulfide presents a fire or explosion hazard. Carbonyl sulfide has a vapor density of 2.1 and is therefore heavier than air. Cylinders or tank cars containing carbonyl sulfide may rupture violently or rocket under fire conditions. 

Freparation. The reagent can be prepared by passing hydrogen sulfide (available in a cylinder from Matheson Co.) into acetic anhydride in the presence of a small amount of powdered sodium hydroxide as catalyst until the proper gain in weight has been realized. ... 

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