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 ...
In chemistry, autoprotolysis is a molecular autoionization, a chemical reaction in which a proton is transferred between two identical molecules, one of which acts as a Brønsted acid, releasing a proton that is accepted by the other molecule, which acts as a Brønsted base. [1]
Autoionization is a process by which an atom or a molecule in an excited state spontaneously emits one of the outer-shell electrons, thus going from a state with charge Z to a state with charge Z + 1, for example from an electrically neutral state to a singly ionized state. [1]
The Henderson–Hasselbalch equation assumes that the autoionization of water is negligible and that the dissociation or hydrolysis of the acid and the base in solution are negligible (in other words, that the formal concentration is the same as the equilibrium concentration).
Pure water has a charge carrier density similar to semiconductors [12] [page needed] since it has a low autoionization, K w = 1.0×10 −14 at room temperature and thus pure water conducts current poorly, 0.055 μS/cm. [13] Unless a large potential is applied to increase the autoionization of water, electrolysis of pure water proceeds slowly ...
For instance, water warms when treated with CaCl 2 (anhydrous calcium chloride) as a consequence of the large heat of hydration. However, the hexahydrate, CaCl 2 ·6H 2 O cools the water upon dissolution. The latter happens because the hydration energy does not completely overcome the lattice energy, and the remainder has to be taken from the ...
Up to 99.63 °C (the boiling point of water at 0.1 MPa), at this pressure water exists as a liquid. Above that, it exists as water vapor. Note that the boiling point of 100.0 °C is at a pressure of 0.101325 MPa (1 atm), which is the average atmospheric pressure.