Safety using mercury

Hazards Place the test tube behind a blast shield during the reaction for safety. Use proper ventilation when handling ammonia, and avoid inhalation of the fumes. Be aware of potential formation of mercury vapor, and use great care. As with any chemical reaction, pay attention and stay focused on what is going on, and what you are doing. 

Metallic (elemental) mercury is widely used in industry and is found in mercury switches and relays. These are components in chest freezers, sump pumps, irons and washing machines (they stop spin cycles or turn on lights and are used in motion-sensitive or position-sensitive safety switches). Mercury-containing relays activate airbags and anti-lock brakes. Mercury is also found in thermostats, thermometers (the small domestic variety contain ... 

Note This procedure is no longer commonly performed in the general chemistry laboratory. Using mercury in an open container in this manner creates health and safety concerns. However, the principle illustrated is the same as in any apparatus that uses a column of mercury for measuring the pressure of a trapped gas. 

The synthesis of monomers derived from fatty acids incorporating end-functions susceptible to classical poly addition reactions has been revived recently and yielded interesting results. Vinyl oleate (VO) and vinyl linoleate (VL) were synthesised by a transvinylation reaction of the corresponding fatty acids with an excess of vinyl acetate (VAc) in bulk using a safe iridium-based catalyst instead of previously used mercury-based counterparts (which are not acceptable today because of safety concerns) [91]. Scheme 4.21 summarises this synthesis in the case of OA. 

The initiating explosive used must ignite with certainty from the spit of a safety fuse. It must be remembered that the intensity of the spit can be reduced if the safety fuse is not cut squarely and also that the fuse may in practice not always be fully inserted into the detonator. Lead azide by itself is not sufficiently easily ignited to give a satisfactory plain detonator and it is therefore used in admixture with lead styphnate, which is very readily ignited by flame. The proportions of such mixtures vary from 25 to 50% of lead styphnate. Mercury fulminate and diazodinitrophenol are sufficiently sensitive to flame not to require such additives. 

This chapter gives an overview of the chlor-alkali industry in Australia and examines the background to the decision to replace the mercury cell plants. It then describes the new plants, their technical and safety features and the process used to arrive at the selection of the technology supplier. 

Detonators are used to detonate high explosives. Stab detonators are initiated by sharp firing pins and are used in explosive trains of different types of fuses. Flash detonators are initiated by flames produced by safety fuses, primers, or delay elements. A special type of flash detonator ignited by the flame of a safety fuse is called a blasting cap. Detonators are primarily composed of three types of explosives including sinoxid mixtures, lead azide-based mixtures, and mercury fulminate-based mixtures. 

Before addition of hydrogen is enabled, use a safety interlock which will not allow addition of hydrogen to the furnace until the furnace has been evacuated to below 50 microns of mercury. 

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