Air, carbon dioxide

Potassium sodium alloy Air, carbon dioxide, carbon disulflde, halocarbons, metal oxides... 

Activated carbons are made by first preparing a carbonaceous char with low surface area followed by controlled oxidation in air, carbon dioxide, or steam. The pore-size distributions of the resulting products are highly dependent on both the raw materials and the conditions used in their manufacture, as maybe seen in Figure 7 (42). 

Oxidative surface treatment processes can be gaseous, ie, air, carbon dioxide, and ozone Hquid, ie, sodium hypochlorite, and nitric acid or electrolytic with the fiber serving as the anode within an electrolytic bath containing sodium carbonate, nitric acid, ammonium nitrate, ammonium sulfate, or other electrolyte. Examples of electrolytic processes are described in the patent Hterature (39,40)... 

Methane -b Air) (Carbon dioxide + Nitrogen + Water + Heat)... 

For materials of equivalent density water-blown polyurethanes and the hydrocarbon-blown polystyrene foams have similar thermal conductivities. This is because the controlling factor determining the conductivity is the nature of the gas present in the cavities. In both of the above cases air, to all intents and purposes, normally replaces any residual blowing gas either during manufacture or soon after. Polyurethane foams produced using fluorocarbons have a lower thermal conductivity (0.12-0.15 Btu in fr h °F ) (0.017-0.022 W/mK) because of the lower conductivity of the gas. The comparative thermal conductivities for air, carbon dioxide and monofluorotrichloromethane are given in Table 27.3. 

Addition polymerization, 148 Air + carbon dioxide, 96, 107, 111 second virial coefficient, 111 Air + ice system, 98 Alkali metals, electronic correlation energy, 252... 

Air, carbon dioxide, hydrogen sulfide, carbonyl sulfide, propane, and sulfur dioxide... 

Larkins et al. (L2) visually observed flow patterns and measured pressure drop and liquid holdup for cocurrent downflow of gas and liquid through beds of spheres, cylinders, and Raschig rings of diameters from 3 mm to f in. in experimental columns of 2- and 4-in. diameter, as well as in a commercial unit several feet in diameter. The fluid media were air, carbon dioxide, or natural gas and water, water containing methylcellulose, water containing soap, ethylene glycol, kerosene, lubricating oil, or hexane. 

The results of a number of workers who have used a variety of gases such as air, carbon dioxide, and steam and of others who have used liquids such as water, acetone, kerosene, and benzene have been correlated by Dnrus and BOELTER-13 who used mixed units for their variables. On converting their relations using consistent (SI, for example) units, they become ... 

Purging vapors from the tank using air, carbon dioxide, or nitrogen... 

Carbon Dioxide. Carbon dioxide, also a colorless and odorless gas, makes up about 0.03% of dry air. Carbon dioxide is introduced into the atmosphere by several natural processes it is released from volcanoes, from burning organic matter, and from living animals as a byproduct of the respiration process. It is for this latter reason that carbon dioxide plays a vital role in the carbon cycle (see Fig. 62), which makes possible one of the more important scientific tools in archaeology, radiocarbon dating (see Textbox 52). 

Some fire extinguishers use C02 because it is denser than air. Carbon dioxide can blanket a fire, because of its heaviness. It prevents oxygen from getting to the fire and as a result, the burning material is deprived of the oxygen it needs to continue burning. 

Potassium permanganate Potassium sodium alloy 2-Propyn-l-ol Organic or readily oxidizable materials Air, carbon dioxide, carbon disulfide, halocarbons, metal oxides Alkali metals, mercury(II) sulfate, oxidizing materials, phosphorus pentoxide, sulfuric acid... 

Methane, also referred to as marsh gas, is a gas composed of carbon and hydrogen with a chemical formula of CH4. It is the first member of the paraffin or alkane series of hydrocarbons. It is lighter than air, colorless, odorless, tasteless and is flammable. It occurs in natural gas and as a by-product of petroleum refining. In atmospheric burning no smoke production normally occurs. In air methane bums with a pale, faintly luminous flame. With excess air carbon dioxide and water vapor is formed during combustion, with an air deficiency carbon monoxide and water is formed. It forms an explosive mixture with air over a moderate range. Its primary uses are as a fuel and raw feedstock for petrochemical products. 

It was around this time that Priestley discovered soda water. Fixed air (carbon dioxide) had long been known to chemists, and Priestley had experimented with it a little. One day he had the idea of trying to dissolve the carbon dioxide in water. He succeeded and found that the water fizzed. Priestley gave some of the soda water to friends and then went on to other kinds of research. Some years later the British Navy expressed interest in the use of Priestley s sparkling water as a remedy for scurvy, but naturally it was unsuccessful. However, soda water quickly became popular in other circles, even earning praise from Lord Byron, who wrote the following stanza on the back of the manuscript of his poem Don Juan ... 

Torbem Bergman (1735-1784) stated that "Bismuth is either native or mineralized by sulfur, perhaps also by acid air [carbon dioxide]. The first ore was found not m Germany, but in Sweden, especially at Riddarhytta (80). 

In 1783 he published an annotated translation of Torbem Bergman s Sciagraphia regni mineralis, and in the following year he communicated to the Philosophical Transactions his Experiments and observations on terra ponderosa (barium carbonate, or witherite) (96). He stated that the specimen he examined came from a lead mine at Alston Moor, on the Pennines of Cumberland. Although he at first mistook it for heavy spar (barite) he soon found it to be a compound of heavy earth (barium oxide) and fixed air (carbon dioxide) (97). 

At this time Lavoisier did not know whether the air of the atmosphere or some part of it was the material fixed in the calcination process. Perhaps because he was entirely ignorant on this matter, he identified it as fixed air (carbon dioxide) of Joseph Black, the only specific example then known of a specific air that could be fixed. It was of course already well known that fixed air was produced from the reduction of metallic calx. 

Once gases were recognized as important in chemical reactions, they were immediately handled in quantitative ways, most conveniently through the measurement of their volumes and densities. Henry Cavendish was apparently the first to measure the densities of gases, as he did with inflammable air (hydrogen) and fixed air (carbon dioxide) in 1766. 

Climate and air Carbon dioxide (CO ) Nitrous oxide (N O) Methane (CH ) Ammonia (NHj)... 

Scheele proved that plumbago, when ignited with saltpeter, was converted into fixed air (carbon dioxide) and assumed therefore that it was composed of that acid and phlogiston, that is, it was the same in composition as charcoal. It will be recalled that Pott had demonstrated that plumbago contained no lead (plumbum) as had been generally assumed by his predecessors. 

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