Search results
Results from the WOW.Com Content Network
The reaction is conveniently conducted with an acetic acid solution of mercury(II) acetate. With gentle heating of the slurry, the black polymorph converts to the red form. [6] β-HgS is unreactive to all but concentrated acids. [4] Mercury is produced from the cinnabar ore by roasting in air and condensing the vapour. [4] HgS → Hg + S
Mercury(I) sulfide or mercurous sulfide is a hypothetical chemical compound of mercury and sulfur, with elemental formula Hg 2 S.Its existence has been disputed; it may be stable below 0 °C or in suitable environments, but is unstable at room temperature, decomposing into metallic mercury and mercury(II) sulfide (mercuric sulfide, cinnabar).
Mechanochemistry (or mechanical chemistry) is the initiation of chemical reactions by mechanical phenomena. Mechanochemistry thus represents a fourth way to cause chemical reactions, complementing thermal reactions in fluids, photochemistry, and electrochemistry. Conventionally mechanochemistry focuses on the transformations of covalent bonds ...
Mercury(II) sulfide, HgS, adopts the cinnabar structure described, and one additional structure, i.e. it is dimorphous. [16] Cinnabar is the more stable form, and is a structure akin to that of HgO : each Hg center has two short Hg−S bonds (each 2.36 Å ), and four longer Hg···S contacts (with 3.10, 3.10, 3.30 and 3.30 Å separations).
For example, mercury sulfide forms when mercuric salts in aqueous solution are treated with thiourea: Hg 2+ + SC(NH 2) 2 + H 2 O → HgS + OC(NH 2) 2 + 2 H + These sulfiding reactions, which have been applied to the synthesis of many metal sulfides, require water and typically some heating. [17] [18]
This article was reviewed by Craig Primack, MD, FACP, FAAP, FOMA. Ah, New Year’s Day. You can set goals at any time of year, of course, but the new year provides that extra rush of motivation.
For many substances, the formation reaction may be considered as the sum of a number of simpler reactions, either real or fictitious. The enthalpy of reaction can then be analyzed by applying Hess' law, which states that the sum of the enthalpy changes for a number of individual reaction steps equals the enthalpy change of the overall reaction.
The rest of the evening passed in a blur. We lit the menorah, gave the kids their gifts, and I forgot all about the bump. But in the middle of the night, a throbbing feeling in my shoulder ...