Mercury is a heavy, silvery and an extremely toxic metal. One of the most popular features the mercury is the in normal conditions this metal is liquid and only freezes at –38.8°C! In nature over there are just two elements that space liquid in normal conditions – mercury and bromine.
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In the earth crust, mercury is a really rare element, however rocks in i m sorry mercury is found usually contain that in quite high concentrations. This is because mercury mixes poorly with elements that consist of most the the earth crust, and also so “accumulations” the minerals containing mercury room formed. The most abundant that them space cinnabar (mercury sulfide HgS) and corderoit (Hg₃S₂Cl₂).
The history of metal
Humanity has actually known about this metal because that a very long time. It was ascribed both mystical and also healing properties. Cinnabar was provided by humans in the Paleolithic era, 30,000 years ago. They painted caves through it. The Ancient Greeks used mercury sulfide in ointments, and Ancient Egyptians and also Romans provided it to make cosmetics. Metallic mercury was uncovered in the tombs of Ancient Egypt, dated 1,600 BCE and the pyramids that Teotihuacan. The Ancient Egyptians and also inhabitants the Mesoamerica may have actually used mercury to make a prototype that the rivers that the afterworld.
Alchemists believed the mercury was the “primary material”, the “substrate” – the foundation that everything in existence. They believed that mercury might turn ordinary metals right into gold.
The metal bring away its name from the Roman God, the patron of traders and also travelers, who is likewise responsible because that communication and also luck. The chemical symbol Hg comes from the Greek word “ὑδράργυρος” (“hydrargyros”), i beg your pardon literally way “water-silver”, as mercury is liquid favor water, and shiny like silver.
Chemical properties of mercury
Mercury does no react v the majority of acids, however dissolves in concentrated sulfuric acid, in nitric acid and in aqua regia. If mercury is inserted in nitric acid, mercury nitrate Hg(NO₃)₂ forms:
Hg + 4HNO₃ → Hg(NO₃)₂ + 2NO₂↑ + H₂O
Mercury is much less reactive than copper, for this reason copper forces mercury the end of its salts. For example, if a copper coin is immersed in a solution that mercury nitrate, metallic mercury settles ~ above the surface the the coin:
Cu + Hg(NO₃)₂ → Cu(NO₃)₂ + Hg↓
One famous experiment with mercury is the mercury heart. Metallic mercury has a solution of sulfuric acid poured end it, and potassium dichromate is added. In this oxidizing medium, ~ above the surface of the autumn of mercury the film of that sulfate forms, reducing the surface tension that gives the autumn its form. As a result the drop of mercury spreads the end a little.
2Hg + SO₄²⁻ → Hg₂SO₄(film) + 2e⁻
Cr₂O₇²⁻ + 14H⁺ + 6e⁻ → 2Cr³⁺ + 7H₂O
If the surface the a fall of mercury is touched through an iron cable or nail, mercury sulfate is reduced to metallic mercury, the movie is broken, the surface tension increases, and the drop “contracts”.
Hg₂SO₄(film) + 2e⁻ → 2Hg↓ + SO₄²⁻
Fe → Fe²⁺ + 2e⁻
When the fall “contracts”, contact through iron is broken, and also the oxidation process of the mercury starts again. The autumn once an ext spreads out, touches iron, and then contracts. This process repeats again and also again, and also the drop throbs like a beating heart.
Where mercury is used
Owing to its toxicity, the usage of mercury today has actually been severely restricted.It deserve to still be uncovered in mercury thermometers, which are becoming a thing of the past. Mercury expands evenly ~ above heating in a quite wide selection of temperatures, and also as that expands and also rises increase the glass capillary, the is simple to judge a readjust in temperature. The truth that it is opaque and also has a characteristic shine provides it convenient to view where the “column” that mercury in the thermometer is located.
Additionally, mercury fumes are supplied in part luminescent lamps. Mercury fumes radiate ultraviolet irradiate if one electric current is passed through them. A special coating top top the surface the the desk lamp converts ultraviolet light into visible light. Among these lamps contains about 10 mg the mercury, and in lamps through a low content the this metal, approximately 4 mg. Additionally, mercury is encountered in some electric switches and also current rectifiers.
Electric batteries room made top top the basis the mercury, however nowadays they have been replaced through other species of batteries and accumulators which do not contain mercury. There was even an attempt to usage mercury as “fuel” because that ionic engines that SERT (Space Electric Rocket Test) spacecraft.
In industry, mercury and also its compounds as offered as catalysts, but one of their widespread applications is the electrolytical production that active metals, chlorine and alkalis (the Castner-Keller process). In this process, a very important property of mercury is used – the ability to form amalgams, and alloys with other metals. Just with iron, platinum, wolfram and also tantalum mercury does not form amalgams.
Amalgams the mercury played a major function in the development the chemistry and also the discovery of new elements. The renowned English chemist teacher Humphrey Davy provided mercury extensively to extract potassium, magnesium, calcium, strontium and also barium by electrochemical methods – amalgams of this metals were developed in the electrolysis that salts and also oxides. Davy then removed the mercury and extracted pure (or almost pure) metals. Additionally, mercury was provided to extract gold from ore, together gold also formed an amalgam with mercury.
Going ago in history, we must discuss other spheres in i m sorry mercury to be widely used. Compounds of this metal were supplied in medicine as diuretics, laxatives, and also medicine because that syphilis. Medication containing mercury to be taken by the English king Henry VIII, Ivan the Terrible and Isaac Newton. In China and Tibet, it to be believed the mercury extended life.
In the 20th century, the compound Thiomersal that contained mercury was supplied to extend the shelf life that vaccines. Mercury and also its nitrate were offered by manufacturers of feel hats in the 18th-19th centuries. Felt to be soaked in a solution the mercury nitrate. Workers had to handle mercury and also breath in that fumes, so poisoning from this metal was a professional illness because that them. As mercury poisoning affected mental health, the expression “mad together a hatter” arose. Over there is a legend that Lewis Carrol based the foolish Hatter indigenous “Alice in Wonderland” ~ above this kind of worker. However, this is probably not the case. The prototype because that the mad Hatter to be an acquaintance of Carrol, the furniture dealer Theophilus Carter.
Mercury is highly toxic. The maximum acceptable concentration of mercury in a room during a working day should not exceed 0.05 mg per cubic meter of air. If a person inhales mercury fumes over a long period the time, serious poisoning will occur, damaging the internal organs and also the nervous system. The person develops symptoms that “madness”: excessive shyness, indecisiveness, phobias, lose of self-identification etc. Additionally, the gums and also the respiratory street become inflamed, bronchitis develops and the digestive organs suffer.
What execute you do if mercury is spilt at house or at work-related – if a mercury thermometer or lamp containing mercury breaks? If a mercury lamp breaks, everyone no involved in cleaning increase the mess should leave the room, and take pets with them. Open up the windows and turn top top the wait conditioning. Put the desk lamp shards in a container that have the right to be close up door or a plastic bag. Tiny shards deserve to be gathered through sticky tape. Climate air the room because that several hours. Don’t use a vacuum cleaner! This may reason the mercury fumes to spread out even more!
If a mercury thermometer breaks, then you should likewise open the windows, and also place the shards that the thermometer in a container or plastic bag. Balls the mercury must be gathered an extremely carefully with a pipette, together they have the property of moving swiftly in different directions. To make sure that no unnoticed drops of mercury have actually been left behind, rotate off the light and also shine a torch throughout the floor – you might notice shining drops i m sorry were not visible in normal light.
The remains that the mercury which cannot it is in collected through a pipette need to be sprinkled v sulfur powder, i m sorry is offered in special sets for removing mercury, or at an ordinary pharmacy. You can likewise use iron(III) chloride, i m sorry is sold at shops because that radio enthusiasts. However if the mercury has fallen top top porous or wooly surfaces (for example a rug), then it is better to throw this items away, as it will be almost impossible to remove mercury from it.
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Remember the the gathered shards and remains the mercury must be dispensed through according come the rules the apply in your area. Girlfriend may discover collection stations because that this type of waste.
Sources:Paul Parsons, Gail Dixon — The Periodic Table A visual overview to the elements;Kristi Lew – Mercury. The Rosen Publishing Group, 2008;Barry R. Leopold – Use and also Release the Mercury in the United States, Contract Nos. 68-C-0027 and also 68-C7-0011, 2002;Waldron, H. A. (1983). Did the mad Hatter have mercury poisoning? brother Medical Journal (Clinical Research Ed.), 287(6409), 1961;John Burke Sullivan, Gary R. Krieger – Clinical Environmental Health and Toxic Exposures. Lippincott Williams & Wilkins, 2001;Sir Humphry Davy – The Collected works of sir Humphry Davy …: Bakerian lectures and miscellaneous papers from 1806 to 1815. Smith, Elder and Company, 1840;