Sulfuric acid or sulphuric acid, known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula H2SO4. It is a colorless, odorless, and viscous liquid that is soluble with water.
In chemistry, a half reaction is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction. Often, the concept of half reactions is used to describe what occurs in an electrochemical cell, such as a Galvanic cell battery. Half reactions can be written to describe both the metal undergoing oxidation and the metal undergoing reduction.
Redox is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction.
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 (FeCl2). The adjective ferric is used instead for iron(III) salts, containing the cation Fe3+. The word ferrous is derived from the Latin word ferrum, meaning "iron".
Iron(II) sulfate (British English: iron(II) sulphate) or ferrous sulfate denotes a range of salts with the formula FeSO4·xH2O. These compounds exist most commonly as the heptahydrate (x = 7) but several values for x are known. The hydrated form is used medically to treat or prevent iron deficiency, and also for industrial applications. Known since ancient times as copperas and as green vitriol (vitriol is an archaic name for hydrated sulfate minerals), the blue-green heptahydrate (hydrate with 7 molecules of water) is the most common form of this material. All the iron(II) sulfates dissolve in water to give the same aquo complex [Fe(H2O)6]2+, which has octahedral molecular geometry and is paramagnetic. The name copperas dates from times when the copper(II) sulfate was known as blue copperas, and perhaps in analogy, iron(II) and zinc sulfate were known respectively as green and white copperas.
In chemistry, a reducing agent is a chemical species that "donates" an electron to an electron recipient.
In environmental chemistry, the chemical oxygen demand (COD) is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed in mass of oxygen consumed over volume of solution, which in SI units is milligrams per liter (mg/L). A COD test can be used to quickly quantify the amount of organics in water. The most common application of COD is in quantifying the amount of oxidizable pollutants found in surface water or wastewater. COD is useful in terms of water quality by providing a metric to determine the effect an effluent will have on the receiving body, much like biochemical oxygen demand (BOD).
A redox indicator is an indicator which undergoes a definite color change at a specific electrode potential.
Chromate salts contain the chromate anion, CrO2−
4. Dichromate salts contain the dichromate anion, Cr
2O2−
7. They are oxyanions of chromium in the +6 oxidation state and are moderately strong oxidizing agents. In an aqueous solution, chromate and dichromate ions can be interconvertible.
The pedosphere is the outermost layer of the Earth that is composed of soil and subject to soil formation processes. It exists at the interface of the lithosphere, atmosphere, hydrosphere and biosphere. The pedosphere is the skin of the Earth and only develops when there is a dynamic interaction between the atmosphere, biosphere, lithosphere and the hydrosphere. The pedosphere is the foundation of terrestrial life on Earth.
1,10-Phenanthroline (phen) is a heterocyclic organic compound. It is a white solid that is soluble in organic solvents. The 1,10 refer to the location of the nitrogen atoms that replace CH's in the hydrocarbon called phenanthrene.
In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation state. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called comproportionation, also known as symproportionation.
Comproportionation or symproportionation is a chemical reaction where two reactants containing the same element but with different oxidation numbers, form a compound having an intermediate oxidation number. It is the opposite of disproportionation.
Indium(III) sulfate (In2(SO4)3) is a sulfate salt of the metal indium. It is a sesquisulfate, meaning that the sulfate group occurs 11/2 times as much as the metal. It may be formed by the reaction of indium, its oxide, or its carbonate with sulfuric acid. An excess of strong acid is required, otherwise insoluble basic salts are formed. As a solid indium sulfate can be anhydrous, or take the form of a pentahydrate with five water molecules or a nonahydrate with nine molecules of water. Indium sulfate is used in the production of indium or indium containing substances. Indium sulfate also can be found in basic salts, acidic salts or double salts including indium alum.
In chemistry, metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlorates. They have the general stoichiometry [M(H2O)n]z+. Their behavior underpins many aspects of environmental, biological, and industrial chemistry. This article focuses on complexes where water is the only ligand, but of course many complexes are known to consist of a mix of aquo and other ligands.
Cerimetry or cerimetric titration, also known as cerate oximetry, is a method of volumetric chemical analysis developed by Ion Atanasiu. It is a redox titration in which an iron(II)–1,10-phenanthroline complex (ferroin) color change indicates the end point. Ferroin can be reversibly discolored in its oxidized form upon titration with a Ce4+ solution. The use of cerium(IV) salts as reagents for volumetric analysis was first proposed in the middle of 19th century, but systematic studies did not start until about 70 years later. Standard solutions can be prepared from different Ce4+ salts, but often cerium sulfate is chosen.
Transition metal complexes of 2,2'-bipyridine are coordination complexes containing one or more 2,2'-bipyridine ligands. Complexes have been described for all of the transition metals. Although few have any practical value, these complexes have been influential. 2,2'-Bipyridine is classified as a diimine ligand. Unlike the structures of pyridine complexes, the two rings in bipy are coplanar, which facilitates electron delocalization. As a consequence of this delocalization, bipy complexes often exhibit distinctive optical and redox properties.
Transition metal sulfate complexes or sulfato complexes are coordination complexes with one or more sulfate ligands. Sulfate binds to metals through one, two, three, or all four oxygen atoms. Common are complexes where sulfate is unidentate or chelating bidentate. Examples are respectively [Co(tren)(NH3)(SO4)]+ (tren = tris(2-aminoethyl)amine) and Co(phen)2SO4. All four oxygen atoms of sulfate bond to metals in some Dawson-type polyoxometalates, e.g. [S2Mo18O62]4-.
Tris(bipyridine)iron(II) chloride is the chloride salt of the coordination complex tris(bipyridine)iron(II), [Fe(C10H8N2)3]2+. It is a red solid. In contrast to tris(bipyridine)ruthenium(II), this iron complex is not a useful photosensitizer because its excited states relax too rapidly, a consequence of the primogenic effect.
Transition metal complexes of 1,10-phenanthroline ("phen") are coordination complexes containing one or more 1,10-phenanthroline ligands. Complexes have been described for many transition metals. In almost all complexes, phen serves as a bidentate ligand, binding metal centers with the two nitrogen atoms. Examples include Mo(CO)4(phen), derived from Mo(CO)6 and [Fe(phen)3]2+.
