Search results
Results from the WOW.Com Content Network
An oxyanion, or oxoanion, is an ion with the generic formula A x O z− y (where A represents a chemical element and O represents an oxygen atom). Oxyanions are formed by a large majority of the chemical elements. [1] The formulae of simple oxyanions are determined by the octet rule. The corresponding oxyacid of an oxyanion is the compound H z ...
Either side of such a line one species or the other predominates, that is, has higher concentration relative to the other species. To illustrate a predominance diagram, part of the one for chromate is shown at the right. pCr stands for minus the logarithm of the chromium concentration and pH stands for minus the logarithm of the hydrogen ion ...
There are very few oxo-aqua ions of metals in the oxidation state +5 or higher. Rather, the species found in aqueous solution are monomeric and polymeric oxyanions. Oxyanions can be viewed as the end products of hydrolysis, in which there are no water molecules attached to the metal, only oxide ions.
The concentration of a dimeric species decreases more rapidly with metal ion concentration than does the concentration of the corresponding monomeric species. Therefore, when determining the stability constants of both species it is usually necessary to obtain data from 2 or more titrations, each with a different metal salt concentration.
The number and identity of the oxyanions that exist between pH 13 and 2 depend on pH as well as concentration. For example, protonation of vanadate initiates a series of condensations to produce polyoxovanadate ions: [2] pH 9–12: HVO 2− 4, V 2 O 4− 7; pH 4–9: H 2 VO − 4, V 4 O 4− 12, HV 10 O 5− 28; pH 2–4: H 3 VO 4, H 2 V 10 O 4 ...
Dissolution of oxides often gives oxyanions. Adding aqueous base to P 4 O 10 gives various phosphates. Adding aqueous base to MoO 3 gives polyoxometalates. Oxycations are rarer, some examples being nitrosonium (NO +), vanadyl (VO 2+), and uranyl (UO 2+ 2). Of course many compounds are known with both oxides and other groups.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
In chemistry, a molybdate is a compound containing an oxyanion with molybdenum in its highest oxidation state of +6: O − −Mo(=O) 2 −O −. Molybdenum can form a very large range of such oxyanions, which can be discrete structures or polymeric extended structures, although the latter are only found in the solid state.