PRODUCTS

ZINC CHLORIDE

CAS No. : 7646-85-7
EC No. : 231-592-0

Synonyms:
Zinc(II) chloride; zinc dichloride; Butter of zinc; 7646-85-7; zinc chloride; Zinc dichloride; Butter of zinc; Zinc(II) chloride; Zinc butter; Zinc chloride (ZnCl2); Zinkchloride; Zintrace; Zinc chloride fume; Zine dichloride; Zinc chloride, (solution); MFCD00011295; Zinc (chlorure de); Zinco (cloruro di); Zinkchlorid [German]; Zinkchloride [Dutch]; Caswell No. 910; Zinc chloride, solution; Chlorure de zinc [French]; Zinc (chlorure de) [French]; CCRIS 3509; Zinco (cloruro di) [Italian]; HSDB 1050; EINECS 231-592-0; UN1840; UN2331; EPA Pesticide Chemical Code 087801; NSC 529648; AI3-04470; Zinc chloride, ultra dry; Zinc Chloride Solution Anhydrous; Zinc chloride solution, 1.9 M in 2-methyltetrahydrofuran; Zinc chloride, 98+%, extra pure; Zinc chloride, 97+%, ACS reagent; Zinc chloride, 98.5%, for analysis; Zinc chloride solution; Zinc chloride, 0.7M solution in THF, AcroSeal(R); Zinc chloride, 2M solution in 2-MeTHF, AcroSeal(R); Zinc chloride, 99.99%, (trace metal basis), anhydrous; Zinc chloride, 99.99%, (trace metal basis), extra pure; Zinc chloride, 1.0M solution in diethyl ether, AcroSeal(R); Zinc chloride 0.1 M solution; Zinc chloride (TN); Zinc muriate, solution; Zinc chloride [USP:JAN]; ZINC CHLORIDE; Zinc chloride [USAN:JAN]; DSSTox_GSID_35013; Zinc chloride (JP17/USP); Zinc chloride, LR, >=97%; Zinc chloride, p.a., 97.0%; Zinc chloride in plastic container; Tox21_301492; Zinc chloride, 1.9M in 2-MeTHF; Zinc chloride, for molecular biology; ZINC CHLORIDE; Zinc chloride, 25mM aqueous solution; Zinc chloride, 0.5M solution in THF; Zinc chloride, 0.7M solution in THF; Zinc chloride, ACS reagent, >=97%; Zinc chloride, reagent grade, >=98%; Zinc chloride solution, 0.5 M in THF9; Zinc chloride (99.99%-Zn) PURATREM; CAS-7646-85-7; FT-0645122; Zinc chloride, 99.999% trace metals basis; Zinc chloride, SAJ first grade, >=95.0%; Zinc chloride, JIS special grade, >=98.0%; D02058; EC 231-592-0; Zinc chloride solution, 1.0 M in diethyl ether; Zinc chloride, anhydrous [UN2331] [Corrosive]; Zinc chloride, solution [UN1840] [Corrosive]; Zinc chloride, solution [UN1840] [Corrosive]; Q204714; Zinc chloride, anhydrous [UN2331] [Corrosive]; BRD-K46586998-001-01-1; Zinc chloride, BioReagent, for molecular biology, >=97.0%; Zinc chloride, anhydrous, powder, >=99.995% trace metals basis; Zinc chloride, anhydrous, free-flowing, Redi-Dri(TM), ACS reagent, >=97%; Zinc chloride, 1M in diethyl ether, packaged under Argon in resealable ChemSeal bottles; Zinc chloride, anhydrous, beads, amorphous, -10 mesh, 99.99% trace metals basis; Zinc chloride, anhydrous, beads, amorphous, -10 mesh, 99.999% trace metals basis; Zinc chloride, anhydrous, free-flowing, Redi-Dri(TM), reagent grade, >=98%; Zinc chloride, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., >=98%; Zinc chloride, puriss., meets analytical specification of Ph. Eur., BP, USP, 98-100.5%; Zinc atomic spectroscopy standard concentrate 1.00 g Zn, 1.00 g/L, for 1L standard solution, analytical standard; Zinc chloride, BioReagent, for molecular biology, suitable for cell culture, suitable for insect cell culture

Zinc Chloride

Zinc chloride is the name of chemical compounds with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. This white salt is hygroscopic and even deliquescent. Samples should therefore be protected from sources of moisture, including the water vapor present in ambient air. Zinc chloride finds wide application in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with this chemical composition is known aside from the very rare mineral simonkolleite, Zn5(OH)8Cl2·H2O.

Properties
Chemical formula ZnCl2
Molar mass 136.315 g/mol
Appearance white crystalline solid
hygroscopic and very deliquescent
Odor odorless
Density 2.907 g/cm3
Melting point 290 °C (554 °F; 563 K)[1]
Boiling point 732 °C (1,350 °F; 1,005 K)[1]
Solubility in water 432.0 g/ 100 g (25 °C)
Solubility soluble in ethanol, glycerol and acetone
Solubility in alcohol 430.0 g/100ml
Magnetic susceptibility (χ) −65.0·10−6 cm3/mol

Hydrates
Five hydrates of zinc chloride are known: ZnCl2(H2O)n with n = 1, 1.5, 2.5, 3 and 4.[14] The tetrahydrate ZnCl2(H2O)4 crystallizes from aqueous solutions of zinc chloride.

Preparation and purification
Anhydrous ZnCl2 can be prepared from zinc and hydrogen chloride:

Zn + 2 HCl → ZnCl2 + H2
Hydrated forms and aqueous solutions may be readily prepared similarly by treating Zn metal, zinc carbonate, zinc oxide, and zinc sulfide with hydrochloric acid:

ZnS + 2 HCl + 4 H2O → ZnCl2(H2O)4 + H2S
Unlike many other elements, zinc essentially exists in only one oxidation state, 2+, which simplifies purification of the chloride.

Commercial samples of zinc chloride typically contain water and products from hydrolysis as impurities. Such samples may be purified by recrystallization from hot dioxane. Anhydrous samples can be purified by sublimation in a stream of hydrogen chloride gas, followed by heating the sublimate to 400 °C in a stream of dry nitrogen gas.[15] Finally, the simplest method relies on treating the zinc chloride with thionyl chloride.[16]

Reactions
Molten anhydrous ZnCl2 at 500–700 °C dissolves zinc metal, and, on rapid cooling of the melt, a yellow diamagnetic glass is formed, which Raman studies indicate contains the Zn2+
2 ion.[14]

A number of salts containing the tetrachlorozincate anion, ZnCl2−4, are known.[10] "Caulton's reagent", V2Cl3(thf)6Zn2Cl6 is an example of a salt containing Zn2Cl2−6. The compound Cs3ZnCl5 contains tetrahedral ZnCl2−4 and Cl− anions. No compounds containing the ZnCl4−6 ion have been characterized.

Whilst zinc chloride is very soluble in water, solutions cannot be considered to contain simply solvated Zn2+ ions and Cl− ions, ZnClxH2O(4−x) species are also present. Aqueous solutions of ZnCl2 are acidic: a 6 M aqueous solution has a pH of 1.[14] The acidity of aqueous ZnCl2 solutions relative to solutions of other Zn2+ salts is due to the formation of the tetrahedral chloro aqua complexes where the reduction in coordination number from 6 to 4 further reduces the strength of the O–H bonds in the solvated water molecules.[22]

In alkali solution in the presence of OH− ion various zinc hydroxychloride anions are present in solution, e.g. Zn(OH)3Cl2−, Zn(OH)2Cl2−2, ZnOHCl2−3, and Zn5(OH)8Cl2·H2O (simonkolleite) precipitates.

When ammonia is bubbled through a solution of zinc chloride, the hydroxide does not precipitate, instead compounds containing complexed ammonia (ammines) are produced, Zn(NH3)4Cl2·H2O and on concentration ZnCl2(NH3)2.[24] The former contains the Zn(NH3)62+ ion,[5] and the latter is molecular with a distorted tetrahedral geometry.[25] The species in aqueous solution have been investigated and show that Zn(NH3)42+ is the main species present with Zn(NH3)3Cl+ also present at lower NH3:Zn ratio.

Aqueous zinc chloride reacts with zinc oxide to form an amorphous cement that was first investigated in the 1855 by Stanislas Sorel. Sorel later went on to investigate the related magnesium oxychloride cement, which bears his name.

When hydrated zinc chloride is heated, one obtains a residue of Zn(OH)Cl e.g.

The formation of highly reactive anhydrous HCl gas formed when zinc chloride hydrates are heated is the basis of qualitative inorganic spot tests.

The use of zinc chloride as a flux, sometimes in a mixture with ammonium chloride (see also Zinc ammonium chloride), involves the production of HCl and its subsequent reaction with surface oxides. Zinc chloride forms two salts with ammonium chloride: (NH4)2ZnCl4 and (NH4)3ClZnCl4, which decompose on heating liberating HCl, just as zinc chloride hydrate does. The action of zinc chloride/ammonium chloride fluxes, for example, in the hot-dip galvanizing process produces H2 gas and ammonia fumes.[31]

Cellulose dissolves in aqueous solutions of ZnCl2, and zinc-cellulose complexes have been detected.[32] Cellulose also dissolves in molten ZnCl2 hydrate and carboxylation and acetylation performed on the cellulose polymer.[33]

Thus, although many zinc salts have different formulas and different crystal structures, these salts behave very similarly in aqueous solution. For example, solutions prepared from any of the polymorphs of ZnCl2, as well as other halides (bromide, iodide), and the sulfate can often be used interchangeably for the preparation of other zinc compounds. Illustrative is the preparation of zinc carbonate:

ZnCl2(aq) + Na2CO3(aq) → ZnCO3(s) + 2 NaCl(aq)
Applications
As a metallurgical flux
Zinc chloride reacts with metal oxides (MO) to give derivatives of the idealized formula MZnOCl2.[34][additional citation(s) needed] This reaction is relevant to the utility of ZnCl2 solution as a flux for soldering — it dissolves passivating oxides, exposing the clean metal surface.[34] Fluxes with ZnCl2 as an active ingredient are sometimes called "tinner's fluid".

In organic synthesis
Zinc chloride is a useful Lewis acid in organic chemistry.[35] Molten zinc chloride catalyses the conversion of methanol to hexamethylbenzene:
15 CH3OH → C6(CH3)6 + 3 CH4 + 15 H2O

Other examples include catalyzing (A) the Fischer indole synthesis,[37] and also (B) Friedel-Crafts acylation reactions involving activated aromatic rings
Related to the latter is the classical preparation of the dye fluorescein from phthalic anhydride and resorcinol, which involves a Friedel-Crafts acylation. This transformation has in fact been accomplished using even the hydrated ZnCl2 sample shown in the picture above.

The combination of hydrochloric acid and ZnCl2, known as the "Lucas reagent", is effective for the preparation of alkyl chlorides from alcohols.

Zinc chloride also activates benzylic and allylic halides towards substitution by weak nucleophiles such as alkenes:[41]

In similar fashion, ZnCl2 promotes selective NaBH3CN reduction of tertiary, allylic or benzylic halides to the corresponding hydrocarbons.

Zinc enolates, prepared from alkali metal enolates and ZnCl2, provide control of stereochemistry in aldol condensation reactions due to chelation on to the zinc. In the example shown below, the threo product was favored over the erythro by a factor of 5:1 when ZnCl2 in DME/ether was used.[43] The chelate is more stable when the bulky phenyl group is pseudo-equatorial rather than pseudo-axial, i.e., threo rather than erythro.

In textile and paper processing
Concentrated aqueous solutions of zinc chloride (more than 64% weight/weight zinc chloride in water) have dissolving starch, silk, and cellulose.

Relevant to its affinity for these materials, ZnCl2 is used as a fireproofing agent and in fabric "refresheners" such as Febreze. Vulcanized fibre is made by soaking paper in concentrated zinc chloride.

Smoke grenades
The zinc chloride smoke mixture ("HC") used in smoke grenades contains zinc oxide, hexachloroethane and granular aluminium powder, which, when ignited, react to form zinc chloride, carbon and aluminium oxide smoke, an effective smoke screen.[44]

Fingerprint detection
Ninhydrin reacts with amino acids and amines to form a colored compound "Ruhemann's purple" (RP). Spraying with a zinc chloride solution forms a 1:1 complex RP:ZnCl(H2O)2, which is more readily detected as it fluoresces more intensely than RP.[45]

Disinfectant and wood preservative
Dilute aqueous zinc chloride was used as a disinfectant under the name "Burnett's Disinfecting Fluid". [46] From 1839 Sir William Burnett promoted its use as a disinfectant as well as a wood preservative.[47] The Royal Navy conducted trials into its use as a disinfectant in the late 1840s, including during the cholera epidemic of 1849; and at the same time experiments were conducted into its preservative properties as applicable to the shipbuilding and railway industries. Burnett had some commercial success with his eponymous fluid. Following his death however, its use was largely superseded by that of carbolic acid and other proprietary products.

Skin cancer treatment
Zinc chloride has been used in alternative medicine to cause eschars, scabs of dead tissue, in an attempt to cure skin cancers.[48] Various products, such as Cansema or "black salve", containing zinc chloride and sold as cancer cures have been listed by the U.S. Food and Drug Administration (FDA) as fake [49] with warning letters being sent to suppliers.[50] Scarring and skin damage are associated with escharotic substances.

Safety
Zinc chloride is a chemical irritant of the eyes, skin, and respiratory system.

General description
Electrodeposition of zinc on glassy carbon and nickel substrates in zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt is studied.[4]

Application
Zinc Chloride may be used:
• as catalyst in knoevenagel condensation of carbonyl substrates with acidic methylene reagents[3]
• in the preparation of porous carbon nanofibers, useful in the fabrication of efficient electrodes for supercapacitors[5]
• as a catalyst in preparation of poly(propylene fumarate)[6]
• in the low temperature synthesis of nanocrystalline zinc oxide films[1]
• in the synthesis of zinc oxide nanoparticles with low agglomeration. Aqueous suspensions of the nanoparticles displayed high transmittance in the visible light range, but exhibited strong absorption in the UV range.

Zinc Chloride is a chemical compound, which is composed of zinc and chlorine. It is a hygroscopic white crystalline ionic salt with the chemical formula ZnCl2. Zinc Chloride is soluble in mediums such as water, glycerol, ether and alcohol. Since Zinc chloride is a deliquescent, it must be protected from sources of moisture such as water vapor.

Synthesis and Purification

Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride.
Zn(s) + 2 HCl → ZnCl2 + H2(g)

Whereas, hydrated and aqueous forms of zinc chloride are prepared by treating zinc with hydrochloric acid. Zinc metal could either be in the form of zinc sulfide or zinc oxide.
ZnS(s) + 2 HCl(aq) → ZnCl2(aq) + H2S(g)

There are impurities present in zinc chloride samples due to hydrolysis. The purification of chloride is simple due to the existence one oxidation state (2+) of zinc. Purification can be done through recrystallization from dioxane (hot). The purification of anhydrous zinc chloride can be done through sublimation with hydrogen chloride gas, followed by the subsequent heating of the sublimate to around 400 °C with dry nitrogen gas. Zinc chloride can also be purified by treating it with thionyl chloride.

USES

Zinc Chloride has numerous applications in different industries, including pharmaceuticals, health care and paper manufacturing industry. Chemical products are also formulated using zinc chloride.

The uses of zinc chloride, based on the type of the industry are as follows:

1. Chemical industry - Zinc chloride is used in the manufacture of various dyes, intermediate chemicals and solvents such as ethyl acetate.

2. Organic product synthesis - Organic products are synthesized in the laboratory for Lewis acid reaction and various other reactions. It also used as a catalyst in organic processes.

3. Metallurgical Industry - It is used a metal etchant and a metallurgical flux. Zinc chloride is used a flux for the soldering process. It is also used in the manufacture of magnesia cement, which is used as an active ingredient for dental fillings and mouthwashes.

4. Printing and Textile industry - Around 64% zinc chloride in water is used to dissolve silk, cellulose and starch. It finds many other applications such as fire proofing agents and fabric refreshers. Vulcanized fibers are manufactured by soaking paper in concentrated zinc chloride. Zinc chloride is used as a mordant in dyeing and printing materials.

5. Petroleum - Zinc chloride is a powerful emulsion breaker, which separates oil from water.

6. Dry cell - Zinc chloride is used in dry cell batteries as an electrolyte.

7. Other Uses - It is used as a condensing agent, dehydrating agent, wood preservative, deodorant and disinfectant.

Conclusion
Zinc chloride finds numerous applications in various industries, and its scope will increase through research, with the course of time. However, this chemical is known to cause skin irritations, gastrointestinal distress, diarrhea, nausea and pulmonary issues, which can be averted through the adoption of apt safety measures at the chemical manufacturing laboratories and plants.

Buy and Sell excess Zinc Chloride online from the best trading portal for the chemical industry.

Zinc chloride had the greatest irritancy potential, causing parakeratosis, hyperkeratosis, inflammatory changes in the epidermis and superficial dermis, and acanthosis of the follicular epithelia.

Receiving
dissolving zinc or its oxide in hydrochloric acid, followed by evaporation of the solution;
heating molten zinc in a chlorine stream.
Application
calico printing;
making dental cements;
antiseptic impregnation of wood (for example, sleepers);
cleaning the surface of metals from oxides before brazing (known as "Soldering acid");
component in the production of fiber;
refining of molten zinc alloys;
fractional analysis of coal samples;
in galvanic cells.
Toxicity
Zinc chloride is highly toxic and a strong irritant. Causes skin burns. Eye contact is especially dangerous.

Zinc Chloride is the name of chemical compounds with the formula ZnCl 2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white and well
soluble in water. ZnCl 2 itself is hygroscopic and even spreads. Therefore, samples must be protected from sources of moisture, including water vapor present in the ambient air.
Zinc chloride is widely used in textile processing, metallurgical fluxes, and chemical synthesis. No mineral with such a chemical composition is known, except very
rare mineral of simoncolleite Zn 5 (OH) 8 Cl 2 · H 2 O.

Zinc chloride is also called zinc chloride and zinc dichloride. Zinc Chloride This chemical reagent has a fairly wide range of applications. Zinc chloride (ZnCl2) is white crystals or flakes, sometimes with a yellowish tinge, capable of absorbing water vapor from the environment.

Main characteristics
- Complete lack of smell.
- Solubility, which differs depending on the temperature of the water. For example, at a temperature of 25 ° C in 100 g of water, you can dissolve 432 g of zinc chloride, and at a temperature of 100 ° C - already 614 g. On average, the compound has 80 percent solubility in water. Along with water, acetone, ethyl alcohol, ether and glycerin are good solvents for zinc chloride.
- Not flammable.
- It is toxic by inhalation, in contact with the skin and mucous membranes, it causes chemical burns, therefore it is necessary to work with this substance using protective equipment.

Production
Industrial production of zinc chloride is carried out in two ways. In the first, zinc is dissolved in hydrochloric acid. Moreover, for this method, both pure zinc and its oxides and even zinc-containing secondary raw materials are suitable. After dissolution, the solution is evaporated.

The second method involves the use of zinc in liquid or (less often) granular form. Chlorine is fed to the zinc, while the zinc is heated to a temperature of 420 ° C.

Zinc chloride is purified by sublimation; production standards are prescribed in GOST 7345-78 and 4529-78.

Storage and transportation
Zinc dichloride The storage area must be dry and well ventilated. It is important to exclude the possibility of spillage and spillage of the compound (if it is transported in the form of a solution), for which it is recommended to use sealed containers. The shelf life, on average, is from 2 months to six months.

Zinc dichloride is transported in accordance with the rules for the carriage of goods that apply to this type of transport. During transportation, the reagent must be hermetically packed, and the container must be marked in accordance with GOST 19433-88.

ZnCl2 is transported and stored usually in sealed tanks or barrels.

Application
Zinc chloride is widely used in completely different fields of industry. The most common areas of its use:
- In dentistry for the production of cements.
- For printing drawings on calico, in the production of dyes, including for dyes of cotton fabrics, in the light industry.
- For the production of refractory impregnations of various materials.
- For oil refining.
- As a dehumidifier.
- In the coal industry - for conducting fractional tests of coal samples.
- In woodworking for antiseptic impregnation of wood.
- In metallurgy for the refining of melts, for the purification of metals from the oxide layer.
- In the manufacture of batteries.

When ammonia is bubbled through a solution of zinc chloride, the hydroxide does not precipitate, instead compounds containing complexed ammonia (ammines) are produced, Zn(NH3)4Cl2·H2O
and on concentration ZnCl2(NH3)2.[23] The former contains the Zn(NH3)62+ ion [4], and the latter is molecular with a distorted tetrahedral geometry.[24] The species in aqueous solution
have been investigated and show that Zn(NH3)42+ is the main species present with Zn(NH3)3Cl+ also present at lower NH3:Zn ratio.

Aqueous zinc chloride reacts with zinc oxide to form an amorphous cement that was first investigated in the 1855 by Stanislas Sorel. Sorel later went on to investigate the related
magnesium oxychloride cement, which bears his name.When hydrated zinc chloride is heated, one obtains a residue of Zn(OH)Cl e.g.

ZnCl2·2H2O → ZnCl(OH) + HCl + H2O
The compound ZnCl2·1⁄2HCl·H2O may be prepared by careful precipitation from a solution of ZnCl2 acidified with HCl. It contains a polymeric anion (Zn2Cl5−)n with balancing monohydrated
hydronium ions, H5O2+ ions.The formation of highly reactive anhydrous HCl gas formed when zinc chloride hydrates are heated is the basis of qualitative inorganic spot tests.

The use of zinc chloride as a flux, sometimes in a mixture with ammonium chloride (see also Zinc ammonium chloride), involves the production of HCl and its subsequent reaction with
surface oxides. Zinc chloride forms two salts with ammonium chloride: (NH4)2ZnCl4 and (NH4)3ClZnCl4, which decompose on heating liberating HCl, just as zinc chloride hydrate does.
The action of zinc chloride/ammonium chloride fluxes, for example, in the hot-dip galvanizing process produces H2 gas and ammonia fumes.

Cellulose dissolves in aqueous solutions of ZnCl2, and zinc-cellulose complexes have been detected.Cellulose also dissolves in molten ZnCl2 hydrate and carboxylation and acetylation
performed on the cellulose polymer.

Thus, although many zinc salts have different formulas and different crystal structures, these salts behave very similarly in aqueous solution. For example, solutions prepared from any
of the polymorphs of ZnCl2, as well as other halides (bromide, iodide), and the sulfate can often be used interchangeably for the preparation of other zinc compounds. Illustrative is
the preparation of zinc carbonate:

ZnCl2(aq) + Na2CO3(aq) → ZnCO3(s) + 2 NaCl(aq)
Applications
As a metallurgical flux
Zinc chloride has the ability to react with metal oxides (MO) to give derivatives of the formula MZnOCl2.[additional citation(s) needed] This reaction is relevant to the utility of
ZnCl2 solution as a flux for soldering — it dissolves oxide coatings, exposing the clean metal surface.[33] Fluxes with ZnCl2 as an active ingredient are sometimes called
"tinner's fluid". Typically this flux was prepared by dissolving zinc foil in dilute hydrochloric acid until the liquid ceased to evolve hydrogen; for this reason, such flux was
once known as "killed spirits". Because of its corrosive nature, this flux is not suitable for situations where any residue cannot be cleaned away, such as electronic work.
This property also leads to its use in the manufacture of magnesia cements for dental fillings and certain mouthwashes as an active ingredient.

In organic synthesis
An early use of zinc chloride (Silzic) was in building carbon skeletons by condensation of methanol molecules. Unsaturated hydrocarbons are the major products, with reaction conditions
influencing the distribution of products, though some aromatic compounds were formed.[34] In 1880, it was found that molten zinc chloride catalyses an aromatization reaction generating
hexamethylbenzene. At the melting point of ZnCl2 (283 °C), the reaction has a ΔG = −1090 kJ/mol and can be idealised as

15 CH3OH → C6(CH3)6 + 3 CH4 + 15 H2O
The discoverers of this reaction rationalized it as involving condensation of methylene units followed by complete Friedel-Crafts methylation of the resulting benzene ring with
chloromethane generated in situ.Such an alkylation transformation is an application of zinc chloride's moderate strength as a Lewis acid, which is its principal role in
laboratory synthesis. Other examples include catalyzing (A) the Fischer indole synthesis,and also (B) Friedel-Crafts acylation reactions involving activated aromatic rings.

Related to the latter is the classical preparation of the dye fluorescein from phthalic anhydride and resorcinol, which involves a Friedel-Crafts acylation.
This transformation has in fact been accomplished using even the hydrated ZnCl2 sample shown.

Hydrochloric acid alone reacts poorly with primary alcohols and secondary alcohols, but a combination of HCl with ZnCl2 (known together as the "Lucas reagent") is effective for
the preparation of alkyl chlorides. Typical reactions are conducted at 130 °C. This reaction probably proceeds via an SN2 mechanism with primary alcohols but SN1 pathway with
secondary alcohols.

Zinc chloride also activates benzylic and allylic halides towards substitution by weak nucleophiles such as alkenes:In similar fashion, ZnCl2 promotes selective NaBH3CN reduction of tertiary, allylic or benzylic halides to the corresponding hydrocarbons.

Zinc chloride is also a useful starting reagent for the synthesis of many organozinc reagents, such as those used in the palladium catalyzed Negishi coupling with aryl halides or vinyl
halides.In such cases the organozinc compound is usually prepared by transmetallation from an organolithium or a Grignard reagent, for example:Zinc enolates, prepared from alkali metal
enolates and ZnCl2, provide control of stereochemistry in aldol condensation reactions due to chelation on to the zinc. In the example shown below, the threo product was favored over
the erythro by a factor of 5:1 when ZnCl2 in DME/ether was used.The chelate is more stable when the bulky phenyl group is pseudo-equatorial rather than pseudo-axial, i.e., threo
rather than erythro.

In textile and paper processing
Concentrated aqueous solutions of zinc chloride (more than 64% weight/weight zinc chloride in water) have the interesting property of dissolving starch, silk, and cellulose.
Thus, such solutions cannot be filtered through standard filter papers. Relevant to its affinity for these materials, ZnCl2 is used as a fireproofing agent and in fabric "refresheners"
such as Febreze. Vulcanized fibre is made by soaking paper in concentrated zinc chloride.

Smoke grenades
The zinc chloride smoke mixture ("HC") used in smoke grenades contains zinc oxide, hexachloroethane and granular aluminium powder, which, when ignited, react to form zinc
chloride, carbon and aluminium oxide smoke, an effective smoke screen.

Fingerprint detection
Ninhydrin reacts with amino acids and amines to form a colored compound "Ruhemann's purple" (RP). Spraying with a zinc chloride solution forms a 1:1 complex RP:ZnCl(H2O)2, which is
more readily detected as it fluoresces better than Ruhemann's purple.

Disinfectant
Historically, a dilute aqueous solution of zinc chloride was used as a disinfectant under the name "Burnett's Disinfecting Fluid". [45] It is also used in some commercial brands of
antiseptic mouthwash.

Skin cancer treatment
Zinc chloride has been used in alternative medicine to cause eschars, scabs of dead tissue, in an attempt to cure skin cancers.[46] Various products, such as Cansema or "black salve",
containing zinc chloride and sold as cancer cures have been listed by the U.S. Food and Drug Administration (FDA) as fake [47] with warning letters being sent to suppliers.

Numerous reports in medical literature describe serious scarring and damage to normal skin by escharotic substances. Given these side-effects, its use in treatment is not warranted as there are much safer and more effective alternatives, such as radiation therapy and Mohs surgery.[49][50]

Safety
Zinc chloride is a skin irritant. After contact of the skin, immediate removal is necessary using soap and plenty of water. After contact of the eyes, adequate measures are rinsing with plenty of water or other eye rinse and contacting an ophthalmologist as soon as possible.[51]

Zinc chloride is caustic to the gastrointestinal tract, occasionally leading to hematemesis. Symptoms of acute intoxication are gastrointestinal distress, diarrhea, nausea, and abdominal pain. Vomiting occurs almost universally. The lethal dose in humans is 3–5 g.[citation needed] Decontamination of the gastrointestinal tract after oral uptake of zinc compounds is mostly unnecessary, since patients usually vomit sufficiently. Milk may be administered to decrease absorption of the metal. Zinc levels may be normalized with EDTA salts.[51]

Zinc chloride is extremely detrimental to the lungs, and pulmonary exposure to zinc chloride smoke has previously resulted in fatalities.Inhalation of fumes of zinc, zinc oxide, or zinc
chloride leads to pulmonary edema and metal fume fever. Onset occurs within 4–6 h and may be delayed up to 8 h. Symptoms include rapid breathing, dyspnea, cough, fever, shivering,
sweating, chest and leg pain, myalgias, fatigue, metallic taste, salivation, thirst, and leukocytosis, which can last from 24 to 48 h. In cases of fume inhalation, cortisone preparations
should be applied immediately (e.g., by inhalation of Auxiloson) to avoid development of lung edema.

Compounds
In chemical compounds, zinc exhibits almost exclusively a +2 oxidation state. A few compounds of zinc in the +1 state have been reported, but never any compounds of zinc in the +3 state or higher.

Zinc chloride is a chemical compound whose formula is ZnCl2, with a molecular weight of 136.3 g / mol. This product is hygroscopic and deliquescent and therefore must be protected from moisture, even that contained in the atmosphere.
Applications:
One of the main applications of zinc chloride is to act as an electrolyte in dry batteries (zinc-carbon). Zinc chloride has the ability to attack the metal oxides, this property allowing its use as flux in the weld metal, dissolving the oxide layers, and leaving the metal surface clean. Zinc chloride is used in various fields such as water treatment, as a fireproofing agent in textile processing and in the manufacture of bactericides, fungicides and stabilizers for plastics.

USES

Dry Cell or Batteries: Zinc Chloride is commonly used in dry cell batteries as an electrolyte where it also acts as a moisture absorbent and corrosion inhibitor. ZnCl2 is an excellent water soluble Zinc source for uses compatible with chlorides. Chloride compounds can conduct electricity when fused or dissolved in water. Chloride materials can be decomposed by electrolysis to chlorine gas and the metal. They are formed through various chlorination processes whereby at least one chlorine anion (Cl-) is covalently bonded to the relevant metal or cation. the item is generally immediately available in most volumes and high purity.

A zinc chloride battery is a heavy duty variation of a zinc carbon battery. It is used in applications that require moderate to heavy current drains. Zinc chloride batteries have better voltage discharge per time characteristics and better low temperature performance than carbon zinc batteries. They batteries are used in radios, flashlights, lanterns, fluorescent lanterns, motor driven devices, portable audio equipments, communications equipments, electronic games, calculators, and remote control transmitters.

Electroplating : Today, there are three primary types of acid zinc plating baths: straight ammonium chloride, straight potassium chloride and mixed ammonium chloride/potassium chloride. Acid zinc plating systems have several advantages over alkaline cyanide and alkaline non-cyanide zinc plating systems except that in acid zinc plating, the electrolyte is extremely corrosive.

Ammonium chloride zinc plating. The ammonium chloride bath is the most forgiving of the three major types of acid zinc plating because of its wide operating parameters. The primary drawback of this system is the high level of ammonia, which can cause problems in wastewater treatment. Ammonia acts as a chelator, and if the rinse waters are not segregated from other waste streams, removal of metals to acceptable levels using standard water treatment practices can be difficult and expensive. Ammonia is also regulated in many communities.

Potassium chloride zinc plating. Potassium chloride zinc plating solutions are attractive because they contain no ammonia. The disadvantages of this system are a greater tendency to burn on extreme edges and higher operating costs. The potassium bath also requires the use of relatively expensive boric acid to buffer the solution and prevent burning in the high-current-density areas, functions performed by the ammonium chloride in the other systems.

Mixed ammonium chloride/potassium chloride zinc plating. This bath combines the best of the ammonia and ammonia-free baths. Because potassium chloride is less expensive than ammonium chloride, the maintenance costs of the mixed bath are lower than the ammonia bath, and it does not require boric acid. The ammonia levels in the rinse waters are low enough that it does not significantly interfere with wastewater treatment, even if plating nickel and copper in the same plant with mixed waste streams. If local regulations restrict the level of ammonia discharged, special waste treatment equipment will be required, and the non-ammonia bath is most likely the best choice.

Galvanizing, Soldering and Tinning Fluxes: Zinc Chloride is used in fluxes for galvanizing, soldering and tinning. Its ability to remove oxides and salts from metal surfaces insures good metal to metal bonding. It has the ability to attack metal oxides (MO) to give derivatives of the formula MZnOCl2. This reaction is relevant to the utility of ZnCl2 as a flux for soldering - it dissolves oxide coatings exposing the clean metal surface. Typically this flux was prepared by dissolving zinc foil in dilute hydrochloric acid until the liquid ceased to evolve hydrogen; for this reason, such flux was once known as killed spirits or "Marela".

Agriculture: It is very rarely used in agriculture. It may be reacted with chelating agents to form solutions of zinc that are biologically available to plants and animals. It's the Chelate manufacturing that consumes Zinc Chloride.

Petroleum: It is an excellent emulsion breaker and is used to separate oil from water. It is also an effective packer fluid in oil and gas wells due to its high specific gravity. However its a little more costly than the other low specific gravity fluids used in the process.

Water Treatment: It is used in specialty corrosion inhibitors in cooling towers, potable water, and in gas and oil wells.

Resins: It is used in Ion - Exchange resins production.

Paints: It is used in for the production of lithopone and as pigment for zinc chromate.

Rubber: It is used as accelerator in the vulcanizing process of rubber.

Glue, wood working: It is used in for the preservation of glue, and for the impregnation of timber.

Printing: It is used in off-set in the chemical products.

Odor Control: It reacts with sulfide to minimize release of H2S gas in waste treatment facilities.

Oil-Gas Wells: High-density solutions of zinc chloride and calcium chloride give good performance in well completion and work-over operations; the solutions also used as packer
fluids under certain well conditions. Zinc chloride has been used in specialty corrosion inhibitors and invert emulsion breakers.

Vulcanized Fiber & Reclaimed Rubber: Water-leaf paper is gelatinized with zinc chloride solution is lesstacky, drier and less moisture-absorbent than caustic reclaimed rubber.
The zinc chloride not only dissolves the cellulosic fibers in the scrap, but also catalyzes depolymerization of the elastomer. Similar method is used for Rubber reclaimed from
natural, styrene-butadiene rubber (SBR), and mixed scrap

Animal drug: Zinc Chloride is used for the production of zinc bacitracin.

Herbicide: Zinc Chloride is used as an herbicide. It is used to control lichen and moss growing on the roofs of houses and other domestic dwellings, along walks, driveways, fences,
and wherever moss grows

Chemical: Zinc Chloride is used in the production of ethyl acetate. It is used as condensing agent for the production of organic dye-stuff. It is used as a stabilizing agent for
diazonium compounds. It is used for the production of active carbon. Zinc Chloride is used for Friedel Craft Reaction, Azotropic or Azeotropic Distillation, Desiccation. Zinc laurate,
linoleate Stearate or resinate can be formed from zinc chloride solutions and solutions of the corresponding sodium salt. Zinc chloride is a Lewis acid and therefore electrophilic in
character. Its catalytic activity is milder than that of aluminum chloride in, for example, Friedel-Crafts type reactions. Zinc chloride is particularly effective in catalyzing reactions
that eliminate molecules of water, ammonia or mercaptans. Its solutions gelatinize cellulosic materials and induce crosslinking in such polymer formers as the methylol ureas. It absorbs
readily on charcoal or silica for catalyzing acylations and alkylations by Friedel-Crafts synthesis. In esterifications and condensation reactions, it facilitates the elimination of
water or ammonia molecules from the reactants. One example is the Fischer idole synthesis.

Miscellaneous:

Zinc Chloride has been used as a catalyst in production of methylene chloride from methyl alcohol.

In the textile industry it has found use in resin systems to impart durable press to cotton and synthetic fabrics.

It has been used in reclaiming rubber where it dissolves rayon cord.

In conjunction with sodium dichromate it has made an excellent wood preservative.

Zinc Chloride has found use in the manufacture of glue, diazo dyes, paper, cosmetics, rayon, synthetic fibers, disinfectants and fire fighting foam.

In ore refining it has been used as a flotation agent.

It is an excellent source of zinc as a starting material in the production of other zinc chemicals and is an effective catalyst for removing molecules of water, ammonia or mercaptants.

Zinc Chloride is used for Friedel Craft Reaction, Azotropic or Azeotropic Distillation, Desiccation & Karl Fischer.

In the laboratory, zinc chloride finds wide use, principally as a moderate-strength Lewis acid. It can catalyze the Fischer indole synthesis and also Friedel-Crafts acylation reactions
involving activated aromatic rings.

Related to the latter is the classical preparation of the dye fluorescein from phthalic anhydride and resorcinol, which involves a Friedel-Crafts acylation.

Hydrochloric acid alone reacts poorly with primary alcohols and secondary alcohols, but a combination of the acid with Zn (known together as the "Lucas reagent") at 130°C is effective
for the preparation of alkyl chlorides. This probably reacts via an SN2 mechanism with primary alcohols but via SN1 with secondary alcohols.

Zinc chloride is also able to activate benzylic and allylic halides towards substitution by weak nucleophiles such as alkenes.

In similar fashion, Zinc Chloride promotes selective NaBH3CN reduction of tertiary, allylic or benzylic halides to the corresponding hydrocarbons.

Zinc chloride is also a useful starting point for the synthesis of many organo zinc reagents, such as those used in the palladium catalyzed Negishi coupling with aryl halides or vinyl
halides. In such cases the organozinc compound is usually prepared by transmetallation from an organolithium or a Grignard reagent.

Zinc enolates, prepared from alkali metal enolates and ZnCl2, provide control of stereochemistry in aldol condensation reactions due to chelation on to the zinc. This is because
the chelate is more stable when the bulky phenyl group is pseudo-equatorial rather than pseudo-axial, i.e., threo rather than erythro.

Zinc chloride, solution is a colorless liquid. It is mildly corrosive to metals. It causes burns to eyes, skin and mucous membranes.

Zinc Chloride is an ionic salt essential for the synthesis of cholesterol, protein, and fats. Zinc plays an important role in the proper functioning of the immune system. Zinc is required for the enzyme activities necessary for cell division, cell growth, and wound healing as well as the release of vitamin A from the liver. It plays a role in the acuity of the senses of smell and taste and is required to maintain prostate reproductive health and insulin function. Zinc is also involved in the metabolism of carbohydrates. Zinc chloride is administered orally or parenterally as a nutritional supplement.

In humans subjected to low doses of (65)zinc chloride and whole-body measurements ... /it was/ estimated absorption to range from 58% to 77% in 5 controls, and from 16% to 42% in 3 patients suffering from acrodermatitis enterohepatica. The whole-body zinc retention was measured for 34 days ... One week after oral tracer dose of 2 ug zinc chloride to mice, the highest concentrations were found in bone tissue followed by liver and kidney.

In mice given 0.3 ugzinc chloride iv, about 50% of the total dose was recovered in feces within a week. the corresponding value in 1 wk for dogs given 6.5 ug zinc chloride was about 20%. Urinary excretion for the same period was well below 5% of the dose in both species ... Biliary excretion of zinc in rats was found to be 4% over a period of 48 hr following a single iv dose of 0.1 mg (65)zinc chloride.

Hepatocytes were grown in monolayer culture for 22 hr and subsequently treated with zinc chloride (100 uM) for 24 hr which produced a 15-fold increase in metallothionein proteins (MT) concentration. Following pretreatment with zinc chloride, hepatocytes were treated with 20 or 40 uM silver nitrate for 24 hr, and cytotoxicity was then assessed by enzyme leakage and loss of intracellular potassium. The toxicity of silver was significantly less in the zinc-pretreated cells. Furthermore, although zinc pretreatment had no appreciable effect on the hepatocellular uptake of silver, it did alter the subcellular distribution, and silver accumulated more in the cytosol and less in the nuclear, mitochondrial, and microsomal fractions. Silver in the cytosol of control cells was bound primarily to high molecular weight proteins, whereas silver was mainly associated with MT in the zinc-pretreated cells. Zinc-induced MT in rat primary hepatocyte cultures protects against silver-induced cytotoxicity which results from the binding of silver to MT with a concomitant reduction of metal content in critical organelles and proteins.

Zinc chloride may be used with copper and chromium cmpd as a wood preservative.

The largest use of zinc chloride in the U.S. is in wood preservatives, fluxes, and batteries.

The largest uses of zinc chloride in the United States are in wood preservation, solder fluxes, and batteries. Solutions of zinc chloride are widely used in mercerizing cotton and as a mordant in dying. In medicine, zinc chloride is used as an antiseptic, disinfectant, deodorant, and in dental cements. Other uses are in organic synthesis, as a dehydrant, in rubber vulcanization, and in oil refining.

The active ingredients covered in this document include zinc chloride, zinc oxide and zinc sulfate monohydrate ... Products containing these active ingredients are used as herbicides, fungicides and bacteriostats for the control of moss, mildew and fungi on structures and adjacent outdoor areas, in carpet, and in pressure treated lumber.

HIgh-purity zinc chloride is formed from zinc and hydrogen chloride gas at 700 °C.

Zinc chloride causes burns ... Data on skin sensitization are not available for zinc chloride. However, based on the accepted derogation and the fact that zinc sulphate is not a skin sensitizer, it is consequently concluded that zinc chloride is not likely to be skin sensitizing.

Employees exposed to zinc chloride should be given instruction in personal hygiene, and in the use of personal protective equipment. Goggles should be provided in areas where danger of spills or splashes exists, skin protection should be provided with rubber gloves, face shields, rubber aprons, gauntlets, suits and rubber boots.

Zinc chloride is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.

Drug products containing certain active ingredients offered over-the-counter (OTC) for certain uses. A number of active ingredients have been present in OTC drug products for various uses, as described below. However, based on evidence currently available, there are inadequate data to establish general recognition of the safety and effectiveness of these ingredients for the specified uses: zinc chloride is included in astringent drug products.

Substances migrating to food from cotton and cotton fabrics used in dry food packaging that are generally recognized as safe for their intended use, within the meaning of section 409 of the Act. Zinc chloride is included on this list.

This brief report describes the clinical course and management of a child who ingested a zinc chloride solution used in a lead soldering process. Injury was limited to bleeding from esophageal erosions and hematemesis. A single small dosage of calcium disodium edetate was effective in normalizing the serum zinc level.

Acute Exposure/ The dermal irritancy of six zinc compounds was examined in three animal models, In open patch tests involving five daily applications, zinc chloride (1% aqueous solution) was severely irritant in rabbit, guinea-pig and mouse tests, inducing epidermal hyperplasia and ulceration; aqueous zinc acetate (20%) was slightly less irritant. Zinc oxide (20% suspension dilute Tween 80), zinc sulphate (1% aqueous solution) and zinc pyrithione (20% suspension) were not overtly irritant, but induced a margina epidermal hyperplasia and increased hair growth. Zinc undecylenate (20% suspension) was not irritant. Epidermal irritancy in these studies is related to the interaction of zinc ion with epidermal keratin. The compounds studied were not consistently bacteriostatic in the three species tested.

Acute Exposure/ In the 10-min inhalation study in female Sprague Dawley rats analytical grade zinc chloride aerosol (generated from solutions of ZnCl2 in water; droplets with mass median aerosol diameter (MMAD) of 2.3 to 2.6 um) was tested, as well as a pyrotechnical mixture (smoke screen) containing zinc chloride and hexachloroethane (which is not of relevance here). With analytical grade zinc chloride aerosol no signs of irritation during or shortly after exposure were seen but signs of respiratory distress developed gradually. Zinc chloride aerosol was lethal to rats at concentrations from 940 mg Zn2+/cu m (ca 1,975 mg ZnCl2/cu m), the animals died within 3 days after exposure. Microscopic findings in the lungs included atelectasis, hyperaemia, hemorrhages and edema, however without a clear-cut dose-response relationship. The LC50 of < or = 1,975 mg/cu m in this study with very small particle size droplets (which might not reflect exposure to inhalable dust under normal conditions) indicates that zinc chloride is toxic by inhalation.

The ability of zinc chloride to induce morphological transformation in Balb/3T3 mouse cells (Cell transformation Assay) was evaluated in the presence of added metabolic activation by Aroclor-induced rat liver S-9 fraction. Based on preliminary clonal toxicity determinations (exposure time = 2hrs), zinc chloride, diluted with phosphate buffered saline, was tested at 200, 400, 600 or 800ug/ml in the presence of metabolic activation, with cell survival ranging from 83% to 1% relative to the solvent control. Treatments at 600 and 800ug/ml were too toxic and the cells failed to grow. Treatments at 200 and 400ug/ml produced significantly greater transformation frequencies (p < 0.05 and p < 0.01, respectively, Modified Poisson Distribution) relative to the solvent control.

The frequency of forward mutations was determined at the thymidine kinase (TK) locus of the mouse lymphoma L5178Y cell line exposed in vitro to zinc chloride in the presence of metabolic activation provided by Aroclor-induced rat liver S9 fraction. Mutagenic effects were observed in cultures after exposure to test article at concentrations ranging from 4.2 to 56 ug/plate, as indicated by 2 to 19.2 fold increases in mean mutant frequency compared to controls. The percent growth ranged from 95% to 10%, while in preliminary cytotoxicity assay, all cells were killed at 50 ug/ml.