Mercury vapour

Any solid mercury compound when fused with sodium carbonate yields a grey deposit of mercury. (Caution mercury vapour is formed.)... 

What would you expect to be the most important features of the He 1 ultraviolet photoelectron spectmm of mercury vapour ... 

The mercury vapour was detected by atomic fluorescence spectrometer Millennium Merlin PSA 10.025. 

The effective absorption of radiation by a gas can be increased by the addition of a sensitizer. For example, when mercuty vapour is added to silane gas, the mercury vapour absorbs radiation to form an excited atom Hg which collides with a silane molecule to lead to partial dissociation... 

If the pump is a filter pump off a high-pressure water supply, its performance will be limited by the temperature of the water because the vapour pressure of water at 10°, 15°, 20° and 25° is 9.2, 12.8, 17.5 and 23.8 mm Hg respectively. The pressure can be measured with an ordinary manometer. For vacuums in the range lO" mm Hg to 10 mm Hg, rotary mechanical pumps (oil pumps) are used and the pressure can be measured with a Vacustat McLeod type gauge. If still higher vacuums are required, for example for high vacuum sublimations, a mercury diffusion pump is suitable. Such a pump can provide a vacuum up to 10" mm Hg. For better efficiencies, the pump can be backed up by a mechanical pump. In all cases, the mercury pump is connected to the distillation apparatus through several traps to remove mercury vapours. These traps may operate by chemical action, for example the use of sodium hydroxide pellets to react with acids, or by condensation, in which case empty tubes cooled in solid carbon dioxide-ethanol or liquid nitrogen (contained in wide-mouthed Dewar flasks) are used. 

Potassium (metal) [7440-09-7] M 39.1, m 62.3 , d 0.89. Oil was removed from the surface of the metal by immersion in n-hexane and pure Et20 for long periods. The surface oxide was next removed by scraping under ether, and the potassium was melted under vacuum. It was then allowed to flow through metal constrictions into tubes that could be sealed, followed by distillation under vacuum in the absence of mercury vapour (see Sodium). EXPLOSIVE IN WATER. 

Mercury vapour in air Diffusive samplers with qualitative onsite colorimetric analysis and quantitative cold vapour atomic absorption spectrometry in the laboratory 59... 

CAUTION. Mercury vapour is a cumulative poison. All vessels containing mercury should be stoppered. Any spilled mercury should be immediately collected and placed in a flask containing water, and the bench (floor) dusted with powdered sulphur. Employ a tray under all vessels containing mercury and for all operations involving the transfer of mercury. 

Instruments for the measurement of fluorescence are known as fluorimeters or spectrofluorimeters. The essential parts of a simple fluorimeter are shown in Fig. 18.1. The light from a mercury-vapour lamp (or other source of ultraviolet light) is passed through a condensing lens, a primary filter (to permit the light band required for excitation to pass), a sample container, a secondary filter (selected to absorb the primary radiant energy but transmit the fluorescent... 

A diagram of a suitable apparatus is shown in Fig. 21.7. The mercury vapour is flushed out of the reaction vessel by bubbling argon through the solution, into the absorption tube. 

Mercaptan 0.5/a Mercaptan 2/a Mercury vapour 0.1 /b Methanol 50/a Methyl acrylate 5/a Methyl bromide 3/a... 

MDHS 14 General method for the gravimetric determination of respirable and total dust MDHS 15 Carbon disulphide MDHS 16 Mercury vapour in air Laboratory method using hopcalite adsorbent tubes, and acid dissolution with cold vapour atomic absorption spectrometric analysis MDHS 17 Benzene in air Laboratory method using charcoal adsorbent tubes, solvent desorption and gas chromatography MDHS 18 Tetra alkyl lead compounds in air Continuous on-site monitoring method using PAC Check atomic absorption spirometry... 

MDHS16 Mercury vapour in air (hopcalite adsorbent tubes). 

Lemington H.26X., made by the General Electric Co., is a very hard borosilicate glass of high softening temperature. Tte Mg point is 780°C. It is used in high pressure mercury vapour lamps. The linear expansion coefficient is 4-6 x 10 from 20 to 580°C. Sodium and potassiiun are absent and alumina is present in quantity in this glass. 

Mercury diffusion pumps are standard pieces of laboratory equipment and, for most cases, quite adequate ones can be constructed from glass. In general, Pyrex glass (or similar glass) is necessary because hot mercury vapour circulates and differential strain is... 

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