Mercury-helium mixtures

Addition of a solute molecule that repels solvent molecules leads in general to em increase of the pressure at constant volume, that is, there is a positive value of dpldx)yT- Equations (6.7) and (6.8) then tell us that the partial molar volume of the solute should diverge toward -i-oo at the critical point of the solvent if there is such a repulsive interaction. This is actually the case for mercury-helium mixtures as illustrated by the pressure dependence of V shown in Fig. 6.5. This simple mechanistic... 

Elements and compounds constitute the world of pure substances. An element is a substance that cannot be decomposed by any chemical reaction into simpler substances. Elements are composed of only one type of atom and all atoms of a given type have the same properties. Pure substances cannot be separated into other kinds of matter by any physical process. We are familiar with many pure substances water, iron, mercury, iodine, helium, rust, diamond, table salt, sugar, gypsum, and so forth. Among the pure substances listed above, iron, mercury, iodine, diamond (pure carbon), and helium are elements. We are also familiar with mixtures of pure substances. These include the air that we breathe, milk, molasses, beer, blood, coffee, concrete, egg whites, ice cream, dirt, steel, and so on. 

Sample Analysis. For analysis via radio gas chromatography the irradiated sample mixture was quantitatively transferred into a greaseless injection loop by means of a 1-L mercury Toepler pump. The chromatography column consisted of 150 ft of 0.25-in. o.d. stainless steel beverage tubing packed with 30 wt % of the crotonic acid ester of H(CF2)8CH20H coated upon 30/40 ASTM mesh Chromosorb PA solid support. The column was operated at 273 K with a helium carrier gas flow rate of 25 cm min" (NTP). 

Accurately known amounts of helium and argon were transferred from calibrated glass bulbs by a mercury-displacement technique. The contents of the cell were separated from the atmosphere by mercury in the U-portion of the cell. The cell was installed in the high-pressure autoclave and the lower part immersed in mercury. The top of the cell was positioned so that the compressed mixture... 

Shortly after the ruby laser came the first gas laser, developed in 1961 in a mixture of helium and neon gases by A. Javan, W. Bennett, and D. Herriott of Bell Laboratories. At the same laboratories, L. F. Johnson and K. Nassau first demonstrated the now well-known and high-power neodymium laser. This was followed in 1962 by the first semiconductor laser demonstrated by R. Hall at the General Electric Research Laboratories. In 1963, C. K. N. Patel of Bell Laboratories discovered the infrared carbon dioxide laser, which later became one of the most powerful lasers. Later that year A. Bloom and E. Bell of Spectra-Physics discovered the first ion laser, in mercury vapor. This was followed in 1964 by the argon ion laser developed by W. Bridges of Hughes Research... 

A gas mixture contains helium and oxygen at partial pressures of 255 torr and 0.450 atm. What is the total pressure, in millimeters of mercury, of the mixture after it is placed in... 

Lobenstein and Dietz deveioped an apparatus not requiring a vacuum system [161]. They adsorbed nitrogen from a mixture of nitrogen and helium in two burettes by continuously raising and lowering attached mercury columns. Equilibrium was established when constant pressure was attained. Additional points were obtained by adding more nitrogen to the system. 

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