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An oxide (/ ˈ ɒ k s aɪ d /) is a chemical compound containing at least one oxygen atom and one other element [1] in its chemical formula. "Oxide" itself is the dianion (anion bearing a net charge of –2) of oxygen, an O 2– ion with oxygen in the oxidation state of −2. Most of the Earth's crust consists of oxides. Even materials ...
4) ions can be found as such in various salts. Many oxyanions of elements in lower oxidation state obey the octet rule and this can be used to rationalize the formulae adopted. For example, chlorine(V) has two valence electrons so it can accommodate three electron pairs from bonds with oxide ions.
Thus, anions (negatively charged ions) are larger than the parent molecule or atom, as the excess electron(s) repel each other and add to the physical size of the ion, because its size is determined by its electron cloud. Cations are smaller than the corresponding parent atom or molecule due to the smaller size of the electron cloud.
The superoxide anion, • O − 2, and the hydroperoxyl radical exist in equilibrium in aqueous solution: • O − 2 + H 2 O ⇌ HO • 2 + HO −. The pK a of HO 2 is 4.88. Therefore, about 0.3% of any superoxide present in the cytosol of a typical cell is in the protonated form. [4] It oxidizes nitric oxide to nitrogen dioxide: [2] • NO ...
The structure of binary oxides can be predicted on the basis of the relative sizes of the metal and oxide ions and the filling of holes in a close packed oxide lattice. However, the predictions of structure are more difficult for ternary oxides. The combination of two or more metals in an oxide creates a lot of structural possibilities.
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
Polyoxomolybdates include the wheel-shaped molybdenum blue anions and spherical keplerates. The cluster [Mo 154 O 420 (NO) 14 (OH) 28 (H 2 O) 70] 20− consists of more than 700 atoms and is the size of a small protein. The anion is in the form of a tire (the cavity has a diameter of more than 20 Å) and an extremely large inner and outer surface.
In chemistry, a mixed oxide is a somewhat informal name for an oxide that contains cations of more than one chemical element or cations of a single element in several states of oxidation. [1] The term is usually applied to solid ionic compounds that contain the oxide anion O 2− and two or more element cations.