sulfate


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.

sulfate

sulfate, chemical compound containing the sulfate (SO4) radical. Sulfates are salts or esters of sulfuric acid, H2SO4, formed by replacing one or both of the hydrogens with a metal (e.g., sodium) or a radical (e.g., ammonium or ethyl). Sulfates in which both hydrogens are replaced are called normal sulfates; sulfates in which only one hydrogen is replaced are called hydrogen sulfates, acid sulfates, or bisulfates. Most metal sulfates are readily soluble in water, but calcium and mercuric sulfates are only slightly soluble, while barium, lead, strontium, and mercurous sulfates are insoluble. In chemical analysis, the sulfate ion, SO4−2, is usually detected by adding barium chloride solution; the white barium sulfate precipitate that forms is insoluble in hydrochloric acid. Sulfates are widely distributed in nature. Barium sulfate occurs as barite; calcium sulfate is found as gypsum, alabaster, and selenite; Epsom salts is magnesium sulfate; sodium sulfate occurs as its decahydrate, Glauber's salt; and strontium sulfate occurs as celestite. Some sulfates were formerly known as vitriols; blue vitriol is cupric sulfate, green vitriol is ferrous sulfate, and white vitriol is zinc sulfate. Alums are double sulfates, containing two different metals and two sulfate radicals. Organic sulfates are esters. They can be formed by reacting an alcohol with cold sulfuric acid. They are also formed by the reaction of sulfuric acid with a double bond in an alkene; the product is called an alkyl hydrogen sulfate. An alkyl hydrogen sulfate can be broken down to an alcohol and sulfuric acid by heating it with water (hydrolysis); this reaction is often used to synthesize alcohols. Sulfates play a significant role both in the chemical industry and in biological systems. Sulfuric acid is used in lead storage batteries and in the manufacture of nitric acid; copper sulfate is a common algicide. Organisms found near deep-sea thermal vents use sulfates for energy in place of sunlight.
The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Sulfate

 

any one of various salts of sulfuric acid, H2SO4. There are two series of sulfates: the normal sulfates, M2SO4, and the acid sulfates, MHSO4, where M is a monovalent metal.

Sulfates are crystalline compounds, which are colorless if the cation is colorless, and in most cases are readily soluble in water. Sparingly soluble sulfates are encountered as the minerals gypsum, CaSO4·2H2O; celestite, SrSO4; and anglesite, PbSO4. The mineral barite, BaSO4, and RaSO4 are virtually insoluble in water. Acid sulfates have been isolated in the solid state only for the most reactive metals, such as sodium and potassium. These salts are readily soluble in water, and they fuse easily. Normal sulfates may be obtained by dissolving metals in sulfuric acid and by the action of sulfuric acid on oxides, hydroxides, and carbonates of metals. Acid sulfates are obtained by heating normal sulfates with concentrated H2SO4:

K2SO4 + H2SO4 = 2KHSO4

The crystal hydrates of the sulfate salts of some heavy metals are called vitriols.

Sulfate minerals are widely used in many branches of industry.

I. K. MALINA

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

sulfate

[′səl‚fāt]
(chemistry)
A compound containing the ‒SO4 group, as in sodium sulfate, Na2SO4.
A salt of sulfuric acid.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
From a chemical point of view, the minerals in the aggregate are mostly inert, and the effect of sulfate on the performance of the aggregate is insignificant [8].
What's more, the Precipitated Barium Sulfate industry development trends and marketing channels are analyzed.
Keo Fish Farm currently uses copper sulfate to treat all its eggs.
Accurately weighed quantity of salbutamol sulfate (10 mg) and ketotifen fumarate (10 mg) was transferred to two separate 10 mL volumetric flasks, dissolved in little amount of methanol and diluted to the mark with methanol (stock solutions: 1000 [micro]g/mL of salbutamol sulfate and ketotifen fumarate).
The American Congress of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) urge caution in regard to the use of magnesium sulfate for fetal neuroprotection.
The composite outcome occurred in 11.3% of the infants of 1,041 women treated with magnesium sulfate during labor versus 11.7% of the infants of 1,095 women who received placebo (relative risk 0.97).
The sulfate content in soils is in a dynamic equilibrium with other forms of sulfur, especially organic forms.
"This rigorous, large-scale study showed that the combination of glucosamine and chondroitin sulfate appeared to help people with moderate to severe pain from knee osteoarthritis, but not those with mild pain," says Stephen Straus, director of the National Center for Complementary and Alternative Medicine at the National Institutes of Health in Bethesda, Maryland.
A new analysis reveals how damage progresses in concrete that's exposed to sulfate, a nearly ubiquitous compound.
External sulfate attack of concrete is a major problem that can appear in regions where concrete is exposed to soil or water containing sulfates, leading to softening and cracking of the concrete.
They were also able to show that the activity was sulfate dependent.