Search results
Results from the WOW.Com Content Network
The self-ionization of water (also autoionization of water, autoprotolysis of water, autodissociation of water, or simply dissociation of water) is an ionization reaction in pure water or in an aqueous solution, in which a water molecule, H 2 O, deprotonates (loses the nucleus of one of its hydrogen atoms) to become a hydroxide ion, OH −.
In chemistry, molecular autoionization (or self-ionization) is a chemical reaction between molecules of the same substance to produce ions. If a pure liquid partially dissociates into ions, it is said to be self-ionizing. [1]: 163 In most cases the oxidation number on all atoms in such a reaction remains unchanged. Such autoionization can be ...
Water is amphoteric, meaning that it can exhibit properties of an acid or a base, depending on the pH of the solution that it is in; it readily produces both H + and OH − ions. [c] Related to its amphoteric character, it undergoes self-ionization. The product of the activities, or approximately, the concentrations of H + and OH −
Electrolysis of pure water requires excess energy in the form of overpotential to overcome various activation barriers. Without the excess energy, electrolysis occurs slowly or not at all. This is in part due to the limited self-ionization of water. Pure water has an electrical conductivity about one hundred thousandth that of seawater. [8] [9 ...
For example, water undergoes autoprotolysis in the self-ionization of water reaction. 2 H 2 O ⇌ OH − + H 3 O + For example, ammonia in its purest form may undergo autoprotolysis: 2 NH 3 ⇌ NH − 2 + NH + 4. Another example is acetic acid: 2 CH 3 COOH ⇌ CH 3 COO − + CH 3 COOH + 2
In pure water, there is an equal number of hydroxide and H + ions, so it is a neutral solution. At 25 °C (77 °F), pure water has a pH of 7 and a pOH of 7 (this varies when the temperature changes: see self-ionization of water). A pH value less than 7 indicates an acidic solution, and a pH value more than 7 indicates a basic solution. [7]
Self-ionization. Water is a weak solution of hydronium ... Water scarcity is also caused by production of water intensive products. For example, cotton: 1 kg of ...
Drinking water quality standards – Quality parameters set for drinking water; Portable water purification – Self-contained, easily transported units used to purify water from untreated sources; Self-ionization of water – Autoprotolysis or exchange of a proton between two water molecules; Water-in-water emulsion