Search results
Results From The WOW.Com Content Network
In chemistry, hydronium (hydroxonium in traditional British English) is the cation [H 3 O] +, also written as H 3 O +, the type of oxonium ion produced by protonation of water.It is often viewed as the positive ion present when an Arrhenius acid is dissolved in water, as Arrhenius acid molecules in solution give up a proton (a positive hydrogen ion, H +) to the surrounding water molecules (H 2 O).
Hydronium is one of a series of oxonium ions with the formula R n H 3−n O +.Oxygen is usually pyramidal with an sp 3 hybridization.Those with n = 1 are called primary oxonium ions, an example being protonated alcohol (e.g. methanol).
By definition, an acid is an ion or molecule that can donate a proton, and when introduced to a solution it will react with water molecules (H 2 O) to form a hydronium ion (H 3 O +), a conjugate acid of water. [4] For simplistic reasoning, the hydrogen ion (H +) is often used to abbreviate the hydronium ion.
An example is the H 2 O (water) molecule, which can gain a proton to form the hydronium ion, H 3 O +, or lose a proton, leaving the hydroxide ion, OH −. The relative ability of a molecule to give up a proton is measured by its pK a value. A low pK a value indicates that the compound is acidic and will easily give up its proton to a base.
The water molecule is amphoteric in aqueous solution. It can either gain a proton to form a hydronium ion H 3 O +, or else lose a proton to form a hydroxide ion OH −. [7] Another possibility is the molecular autoionization reaction between two water molecules, in which one water molecule acts as an acid and another as a base.
H + 3 is one of the most abundant ions in the universe, and it plays a notable role in the chemistry of the interstellar medium. [101] Neutral triatomic hydrogen H 3 can exist only in an excited form and is unstable. [102] By contrast, the positive hydrogen molecular ion (H + 2) is a rare in the universe. [citation needed]
Protons tunnel across a series of hydrogen bonds between hydronium ions and water molecules.. The Grotthuss mechanism (also known as proton jumping) is a model for the process by which an 'excess' proton or proton defect diffuses through the hydrogen bond network of water molecules or other hydrogen-bonded liquids through the formation and concomitant cleavage of covalent bonds involving ...
The hydrogensulfate ion (HSO − 4), also called the bisulfate ion, is the conjugate base of sulfuric acid (H 2 SO 4). [ 59 ] [ b ] Sulfuric acid is classified as a strong acid; in aqueous solutions it ionizes completely to form hydronium ( H 3 O + ) and hydrogensulfate ( HSO − 4 ) ions.