Zinc sulfate

Zinc sulfate

Names
IUPAC name Zinc sulfate
Other names White vitriol Goslarite
Identifiers
CAS Number	7733-02-0 Y 7446-19-7 (monohydrate) N 13986-24-8 (hexahydrate) N 7446-20-0 (heptahydrate) N
3D model (JSmol)	Interactive image
ChEBI	CHEBI:35176 Y
ChemSpider	22833 Y
ECHA InfoCard	100.028.904
EC Number	231-793-3
PubChem CID	24424
RTECS number	ZH5260000
UNII	0J6Z13X3WO Y
UN number	3077
InChI InChI=1S/H2O4S.Zn/c1-5(2,3)4;/h(H2,1,2,3,4);/q;+2/p-2 Y Key: NWONKYPBYAMBJT-UHFFFAOYSA-L Y InChI=1/H2O4S.Zn/c1-5(2,3)4;/h(H2,1,2,3,4);/q;+2/p-2 Key: NWONKYPBYAMBJT-NUQVWONBAU
SMILES [Zn+2].[O-]S([O-])(=O)=O
Properties
Chemical formula	ZnSO4
Molar mass	161.47 g/mol (anhydrous) 179.47 g/mol (monohydrate) 287.53 g/mol (heptahydrate)
Appearance	white powder
Odor	odorless
Density	3.54 g/cm3 (anhydrous) 2.072 g/cm3 (hexahydrate)
Melting point	680 °C (1,256 °F; 953 K) decomposes (anhydrous) 100 °C (heptahydrate) 70 °C, decomposes (hexahydrate)
Boiling point	740 °C (1,360 °F; 1,010 K) (anhydrous) 280 °C, decomposes (heptahydrate)
Solubility in water	57.7 g/100 mL, anhydrous (20 °C) (In aqueous solutions with a pH < 5)[1]
Solubility	alcohols
Magnetic susceptibility (χ)	−45.0·10−6 cm3/mol
Refractive index (nD)	1.658 (anhydrous), 1.4357 (heptahydrate)
Thermochemistry
Std molar entropy (So298)	120 J·mol−1·K−1[2]
Std enthalpy of formation (ΔfHo298)	−983 kJ·mol−1[2]
Pharmacology
ATC code	A12CB01 (WHO)
Hazards
Safety data sheet	ICSC 1698
EU classification (DSD) (outdated)	Harmful (Xn) Dangerous for the environment (N)
R-phrases (outdated)	R22, R41, R50/53
S-phrases (outdated)	(S2), S22, S26, S39, S46, S60, S61
Flash point	Non-flammable
Related compounds
Other cations	Cadmium sulfate Manganese sulfate
Related compounds	Copper(II) sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Zinc sulfate is an inorganic compound and dietary supplement. As a supplement it is used to treat zinc deficiency and to prevent the conditions in those at high risk.^[3] Side effects may include abdominal pain, vomiting, headache, and tiredness.^[4]

It has the formula ZnSO₄ as well as any of three hydrates. It was historically known as "white vitriol". All of the various forms are colourless solids. The heptahydrate form is commonly encountered.^[5]

Uses

Medicine

In medicine it is used together with oral rehydration therapy (ORT) and an astringent.^[5]

Manufacturing

The hydrates, especially the heptahydrate, are the primary forms used commercially. The main application is as a coagulant in the production of rayon. It is also a precursor to the pigment lithopone.

It is used as in electrolytes for zinc plating, as a mordant in dyeing, as a preservative for skins and leather.

Other

Zinc sulfate is used to supply zinc in animal feeds, fertilizers, toothpaste, and agricultural sprays. Zinc sulfate, like many zinc compounds, can be used to control moss growth on roofs.^[6]

Zinc sulfate can be used to supplement zinc in the brewing process. Zinc is a necessary nutrient for optimal yeast health and performance. Although not necessary for low gravity beers as the grains commonly used in brewing already provide adequate zinc. It is a more common practice when pushing yeast to their limit by increasing alcohol content beyond their comfort zone. Before modern stainless steel brew kettles and fermenting vessels and after wood, zinc was slowly leeched by the use of copper kettles. A modern copper immersion chiller is speculated to provide trace elements of zinc. Be careful when adding supplemental zinc to not overdo it. Side effects include "...increased acetaldehyde and fusel alcohol production due to high yeast growth when zinc concentrations exceed 5 ppm. Excess zinc can also cause soapy or goaty flavors." ^{[7] [8]} [Sillerova et al. (2012) Journal of Microbiology, Biotechnolgy and Food Sciences 1 (February special issue): 689-695]

Toxicity

Zinc sulfate powder is an eye irritant. Ingestion of trace amounts is considered safe, and zinc sulfate is added to animal feed as a source of essential zinc, at rates of up to several hundred milligrams per kilogram of feed. Excess ingestion results in acute stomach distress, with nausea and vomiting appearing at 2-8 mg/Kg of body weight.^[9]

Production and reactivity

Zinc sulfate is produced by treating virtually any zinc containing material (metal, minerals, oxides) with sulfuric acid.^[5]

Specific reactions the reaction of the metal with aqueous sulfuric acid:

Zn + H₂SO₄ + 7 H₂O → ZnSO₄(H₂O)₇ + H₂

Pharmaceutical grade zinc sulfate is produced by treating high purity zinc oxide with sulfuric acid:

ZnO + H₂SO₄ + 6 H₂O → ZnSO₄(H₂O)₇

In aqueous solution, all forms of zinc sulfate behave identically. These aqueous solutions consist of the metal aquo complex [Zn(H₂O)₆]²⁺ and SO₄²⁻ ions. Barium sulfate forms when these solutions are treated with solutions of barium ions:

ZnSO₄ + BaCl₂ → BaSO₄ + ZnCl₂

With a reduction potential of -0.76, zinc(II) reduces only with difficulty.

When heated over 680 C, zinc sulfate decomposes into sulfur dioxide gas and zinc oxide fume, both of which are hazardous.^[10]

Minerals

As a mineral ZnSO₄·7H₂O is known as goslarite. Zinc sulfate occurs as several other minor minerals Zinc-melanterite (Zn,Cu,Fe)SO₄·7H₂O (structurally different from goslarite). Lower hydrates of zinc sulfate are rarely found in nature: (Zn,Fe)SO₄·6H₂O (bianchite ), (Zn,Mg)SO₄·4H₂O (boyleite), and (Zn,Mn)SO₄·H₂O (gunningite).

References