Hydrogen sulfide physical properties

Physical Properties. Hydrogen sulfide, H2S, is a colorless gas having a characteristic rotten-egg odor. The physical properties of hydrogen sulfide are given in Table 2. 

Table 2. Physical and Thermodynamic Properties of Hydrogen Sulfide...

One of the most effective methods of preventing corrosion is the selection of the proper metal or alloy for a particular corrosive service. Once the conditions of service and environment have been determined that the equipment must withstand, there are several materials available commercially that can be selected to perform an effective service in a compatible environment. Some of the major problems arise from popular misconceptions for example, the use of stainless steel. Stainless steel is not stainless and is not the most corrosion-resistant material. Compatibility of material with service environment is therefore essential. For example, in a hydrogen sulfide environment, high-strength alloys (i.e., yield strength above 90,000 psi or Rc 20 to 22) should be avoided. In material selection some factors that are important to consider are material s physical and chemical properties, economics and availability. 

These experts collectively have knowledge of hydrogen sulfide s physical and chemical properties, toxicokinetics, key health end points, mechanisms of action, human and animal exposure, and quantification of risk to humans. All reviewers were selected in conformity with the conditions for peer review specified in Section 104(I)(13) of the Comprehensive Environmental Response, Compensation, and Liability Act, as amended. 

Information regarding the physical and chemical properties of hydrogen sulfide is located in Table 3-2. 

Physical and Chemical Properties. Information is available on the physical and chemical properties of hydrogen sulfide (ACGIH 1991 Amoore and Hautala 1983 Budavari et al. 1996 HSDB 1998 Leonardos et al. 1969 Lide and Frederikse 1993 NIOSH 1997). However, additional information on those properties that determine the specific fate, transport, and rates of transformation of hydrogen sulfide as part of the larger sulfur cycle would be useful in discerning the environmental fate and behavior of this compound. 

Anhydrous copper(II) sulfate, 7 773 Anhydrous ethanol, production by azeotropic extraction, 8 809, 817 Anhydrous gaseous hydrogen sulfide, 23 633 Anhydrous hydrazine, 13 562, 585 acid-base reactions of, 13 567-568 explosive limits of, 13 566t formation of, 13 579 vapor pressures of, 13 564 Anhydrous hydrogen chloride, 13 809-813 physical and thermodynamic properties of, 13 809-813 purification of, 13 824-825 reactions of, 13 818-821 uses for, 13 833-834... 

Liquid hydrazine, 13 586 Liquid hydrocarbons, in fluidized-bed processes, 20 169-170 Liquid hydrogen delivery of, 13 853 energy density of, 13 839 physical and thermodynamic properties of, 13 762-763t as a rocket fuel, 13 800 storage of, 13 785-786 Liquid hydrogen sulfide, 23 630, 633 Liquid hydrogen tank levitation system, 23 866... 

Elemental composition (anhydrous salt) Pt 47.60%, H 0.49%, Cl 51.90%. The compound may be identified by its physical and chemical properties. Platinum in an aqueous solution of the compound can be analyzed by flame AA or ICP spectroscopy. Also, the compound can be measured by gravimetry following precipitation with ammonium chloride, hydrogen sulfide, or silver nitrate (see Reactions above). 

Production of sulfides. This may involve the production of FeS, Fe (OH)2 etc. and an aggressive chemical agent such as hydrogen sulfide (H2S) or acidity. Micro-organisms may also consume chemical species that are important in corrosion reactions (e.g., oxygen or nitrite inhibitors). Alternatively, their physical presence may form a slime or poultice, which leads to differential aeration cell attack or crevice corrosion. They may also break down the desirable physical properties of lubricating oils or protective coatings. (Stott)5... 

Hydrogen sulfide is a colorless, flammable gas at ambient temperature and pressure. It is an irritant and asphyxiant and has an offensive odor similar to rotten eggs. It has been reported that people can smell hydrogen sulfide at concentrations as low as 0.5 parts per billion (ppb) of air (ATSDR 1999). Hydrogen sulfide has an odor threshold of 0.02-0.13 parts per million (ppm) (Beauchamp et al. 1984). Olfactory fatigue (which causes a loss of odor perception) can occur at 100 ppm, and paralysis of the olfactory nerve has been reported at 150 ppm (Beauchamp et al. 1984). The chemical and physical properties of hydrogen sulfide are summarized in Table 7-1. 

TABLE 7-1 Physical and Chemical Properties for Hydrogen Sulfide ... 

Information regarding the physical and chemical properties of benzene is shown in Table 3-2. The major impurities found in commercial products are toluene, xylene, phenol, thiophene, carbon disulfide, acetylnitrile and pyridine (NIOSH 1974). Commercial refined benzene-535 is free of hydrogen sulfide and sulfur dioxide, but contains a maximum of 1 ppm thiophene and a maximum of 0.15% nonaromatics. Refined nitration-grade benzene is free of hydrogen sulfide and sulfur dioxide. Benzene is also commercially available as thiophene-free, 99 mole%, 99.94 mole% and nanograde quality (HSDB 1996). 

In this chapter, techniques are presented for estimating the physical properties of fluids along with some recommended values for hydrogen sulfide, carbon dioxide, methane, and water - the last two being the major impurities in acid gas. However, we will concentrate on the physical properties of hydrogen sulfide and carbon dioxide and mixtures of these two components. 

Many physical properties of covalent molecular solids are due to intermolecular forces. The melting and boiling points of molecular substances are relatively low compared with those of ionic substances. That s why salt doesn t melt when you heat it but sugar does. Many molecular substances exist as gases or vaporize readily at room temperature. Oxygen (O2), carbon dioxide (CO2), and hydrogen sulfide (H2S) are examples of covalent gases. Hardness is also due to the intermolecular forces between individual molecules, so covalent molecules form relatively soft solids. Paraffin is a common example of a covalent solid. 

---