Zinc amalgam is a solution of

zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...

in mercury. In practice the term refers to particles of zinc with a surface coating of the

amalgam Amalgam most commonly refers to: * Amalgam (chemistry), mercury alloy * Amalgam (dentistry), material of silver tooth fillings ** Bonded amalgam, used in dentistry Amalgam may also refer to: * Amalgam Comics, a publisher * Amalgam Digital, an in ...

. A gray solid, it is typically used for reduction. It is written as Zn(Hg) in reactions. It is usually prepared by treating an aqueous suspension of zinc with

mercuric chloride Mercury(II) chloride (mercury bichloride, mercury dichloride, mercuric chloride), historically also sulema or corrosive sublimate, is the inorganic chemical compound of mercury and chlorine with the formula HgCl2, used as a laboratory reagent. ...

. Some

zinc chloride Zinc chloride is an Inorganic chemistry, inorganic chemical compound with the chemical formula, formula ZnCl2·''n''H2O, with ''n'' ranging from 0 to 4.5, forming water of hydration, hydrates. Zinc chloride, anhydrous and its hydrates, are colo ...

is produced in the process.

Uses

* Used from ~1837 to reduce 'local action' which degraded operation of

Voltaic pile upright=1.2, Schematic diagram of a copper–zinc voltaic pile. Each copper–zinc pair had a spacer in the middle, made of cardboard or felt soaked in salt water (the electrolyte). Volta's original piles contained an additional zinc disk at the ...

s. See History of the battery#Invention. * To reduce ferric to

ferrous ion In chemistry, iron(II) refers to the element iron in its +2 oxidation state. The adjective ''ferrous'' or the prefix ''ferro-'' is often used to specify such compounds, as in ''ferrous chloride'' for iron(II) chloride (). The adjective ''ferr ...

s in solution. See

Jones reductor A Jones reductor is a device used to reduce aqueous solutions of metal ions. The active component is a zinc amalgam. Jones reductors have been used for preparing solutions of titanium(III), vanadium(II), chromium(II), molybdenum(III), niobium(II ...

. * To reduce

ketone In organic chemistry, a ketone is an organic compound with the structure , where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group (a carbon-oxygen double bond C=O). The simplest ketone is acetone ( ...

s and

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

s to

alkane In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in whi ...

s via the

Clemmensen reduction Clemmensen reduction is a chemical reaction described as a Redox, reduction of ketones or aldehydes to alkanes using zinc Amalgam (chemistry), amalgam and concentrated hydrochloric acid (HCl). This reaction is named after Erik Christian Clemmensen ...

in acidic conditions.

References

Electrochemistry Metallurgy Zinc alloys Mercury (element) Amalgams {{metallurgy-stub