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[3] [4] It is a basic oxide dissolving in acids to give solutions of vanadium (III) complexes. [4] V 2 O 3 has the corundum structure. [ 4 ] It is antiferromagnetic with a critical temperature of 160 K. [ 5 ] At this temperature there is an abrupt change in conductivity from metallic to insulating. [ 5 ]
A basic oxide, also called a base anhydride (meaning "base without water"), is usually formed in the reaction of oxygen with metals, especially alkali (group 1) and alkaline earth (group 2) metals. Both of these groups form ionic oxides that dissolve in water to form basic solutions of the corresponding metal hydroxide :
In strongly acidic solutions, pH < 2, [VO 2 (H 2 O) 4] + is the predominant species, while the oxide V 2 O 5 precipitates from solution at high concentrations. The oxide is formally the acid anhydride of vanadic acid. The structures of many vanadate compounds have been determined by X-ray crystallography.
Dihydrogen monoxide is a name for the water molecule, which comprises two hydrogen atoms and one oxygen atom (H 2 O).. The dihydrogen monoxide parody is a parody that involves referring to water by its unfamiliar chemical systematic name "dihydrogen monoxide" (DHMO, or the chemical formula H 2 O) and describing some properties of water in a particularly concerning manner — such as the ...
The cationic metal centres act as Lewis acid sites while the anionic oxygen centres act as Lewis bases. Surface hydroxyl groups can serve as Brønsted acid or base sites as they can give up or accept a proton. [14] The surface of most metal oxides will be, to some extent, hydroxylated under normal conditions when water vapor is present. [15]
Carbonic acid is an illustrative example of the Lewis acidity of an acidic oxide. CO 2 + 2OH − ⇌ HCO 3 − + OH − ⇌ CO 3 2− + H 2 O. This property is a key reason for keeping alkali chemicals well sealed from the atmosphere, as long-term exposure to carbon dioxide in the air can degrade the material.
If acid is slowly added to a solution of Na 3 VO 4, the colour gradually deepens through orange to red before brown hydrated V 2 O 5 precipitates around pH 2. These solutions contain mainly the ions HVO 4 2− and V 2 O 7 4− between pH 9 and pH 13, but below pH 9 more exotic species such as V 4 O 12 4− and HV 10 O 28 5− ( decavanadate ...
The charge of a molecule depends upon the pH of its solution. In an acidic medium, basic drugs are more charged and acidic drugs are less charged. The converse is true in a basic medium. For example, Naproxen is a non-steroidal anti-inflammatory drug that is a weak acid (its pKa value is 5.0). The gastric juice has a pH of 2.0. It is a three ...