Editing Mercury(II) chloride (section)

==Applications==
The main application of mercuric chloride is as a [[catalyst]] for the conversion of [[acetylene]] to [[vinyl chloride]], the precursor to [[polyvinyl chloride]]:
:C<sub>2</sub>H<sub>2</sub>  +  HCl   →   CH<sub>2</sub>=CHCl
For this application, the mercuric chloride is supported on carbon in concentrations of about 5 weight percent. This technology has been eclipsed by the thermal cracking of [[1,2-dichloroethane]]. Other significant applications of mercuric chloride include its use as a [[depolarizer]] in batteries and as a reagent in [[organic synthesis]] and [[analytical chemistry]] (see below).<ref>Matthias Simon, Peter Jönk, Gabriele Wühl-Couturier, Stefan Halbach "Mercury, Mercury Alloys, and Mercury Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2006: Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a16_269.pub2}}</ref>
It is being used in plant tissue culture for surface sterilisation of explants such as leaf or stem nodes.

===As a chemical reagent===
Mercuric chloride is occasionally used to form an [[amalgam (chemistry)|amalgam]] with metals, such as [[aluminium]].<ref>{{cite journal|doi=10.15227/orgsyn.092.0013|title=Synthesis of 4,4-Dimethoxybut-1-yne|journal=Organic Syntheses|volume=92|pages=13–25|year=2015|last1=Deng|first1=James|first2=Yu-Pu|last2=Wang|first3=Rick L.|last3=Danheiser|doi-access=free}}</ref>  Upon treatment with an aqueous solution of mercuric chloride,  aluminium strips quickly become covered by a thin layer of the amalgam. Normally, aluminium is protected by a thin layer of oxide, thus making it inert.  Amalgamated aluminium exhibits a variety of reactions not observed for aluminium itself. For example, amalgamated aluminum reacts with water generating Al(OH)<sub>3</sub> and hydrogen gas.   [[Halocarbon]]s react with amalgamated aluminium in the [[Barbier reaction]]. These alkylaluminium compounds are [[nucleophilic]] and  can be used in a similar fashion to the Grignard reagent. Amalgamated aluminium is also used as a [[Redox|reducing agent]] in organic synthesis.  Zinc is also commonly amalgamated using mercuric chloride.

Mercuric chloride is used to remove [[dithiane]] groups attached to a carbonyl in an [[umpolung]] reaction.  This reaction exploits the high affinity of Hg<sup>2+</sup> for anionic sulfur ligands.

Mercuric chloride may be used as a stabilising agent for chemicals and analytical samples. Care must be taken to ensure that detected mercuric chloride does not eclipse the signals of other components in the sample, such as is possible in [[gas chromatography]].<ref>{{Cite journal | doi = 10.1021/es00031a004| title = Analytical interferences of mercuric chloride preservative in environmental water samples: Determination of organic compounds isolated by continuous liquid-liquid extraction or closed-loop stripping| journal = Environmental Science & Technology| volume = 26| issue = 7| pages = 1307| year = 1992| last1 = Foreman | first1 = W. T. | last2 = Zaugg | first2 = S. D. | last3 = Faires | first3 = L. M. | last4 = Werner | first4 = M. G. | last5 = Leiker | first5 = T. J. | last6 = Rogerson | first6 = P. F. | bibcode = 1992EnST...26.1307F}}</ref>