Bases


 * Please stop plagiarizing from Wikipedia! They have this paragraph verbatim at the top of their page. Curious, as they also seem to have stolen it from http://www.ovguide.com/base-9202a8c04000641f800000000010c024. Please fix what you have stolen. **

A **base** in chemistry is a substance that can accept hydrogen ions ( protons ) or more generally, donate electron pairs. A soluble base is referred to as an ** alkali ** if it contains and releases hydroxide ions ( OH− ) quantitatively. The Brønsted-Lowry theory defines bases as proton (hydrogen ion) acceptors, while the more general Lewis theory defines bases as electron pair donors, allowing other Lewis acids than protons to be included. The oldest Arrhenius theory defines bases as hydroxide anions, which is strictly applicable only to alkali. In water, by altering the autoionization equilibrium, bases give solutions with a hydrogen ion activity lower than that of pure water, i.e. a [|pH] higher than 7.0 at standard conditions. Metal oxides, hydroxides and especially alkoxides are basic, and counteranions of weak acids are weak bases. Bases can be thought of as the chemical opposite of acids. A reaction between an acid and base is called neutralization. Bases and acids are seen as opposites because the effect of an acid is to increase the hydronium ion ( H 3  O+ ) concentration in water, whereas bases reduce this concentration. Bases and acids are typically found in aqueous solution forms. Aqueous solutions of bases react with aqueous solutions of acids to produce water and salts in aqueous solutions in which the salts separate into their component ions. If the aqueous solution is a saturated solution with respect to a given salt solute any additional such salt present in the solution will result in formation of a precipitate of the salt.

Properties
Some general properties of bases include
 * Slimy or soapy feel on fingers, due to saponification of the lipids in human skin.
 * Concentrated or strong bases are caustic on organic matter and react violently with acidic substances.
 * Aqueous solutions or molten bases dissociate in ions and conduct electricity.
 * Reactions with indicators : bases turn red litmus paper blue, phenolphthalein pink, keep bromothymol blue in its natural colour of blue, and turns methyl orange yellow.
 * The pH level of a basic solution is higher than 7.
 * Bases are bitter in taste.
 * Bases produce hydroxide anion (OH-) when dissolved in water solutions.
 * Bases are substances that can accept hydrogen ions.
 * A soluble base is refered to as an alkali; only if it contains and releases hydrogen ions.
 * Except for sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide and ammonia, other bases cannot be dissolved in water.
 * Some bases can react with acidic gas (e.g. CO 2 ) producing salt and water.

general formula YOH = Y+ (aq) + OH- (aq)

Hydroxide

A base is any compound that yields hydroxide ions (OH-) when dissolved in water. There are quite a few identifiable bases with hydroxide in the the formula such as sodium hydroxide (NaOH) and magnesium hydroxide (Mg(OH) 2 ).

Self Ionization Reaction:

NaOH ---> Na+ + OH-

Bases have pH levels higher than 7.

Common bases include: Ammonium Hydroxide(NH 4 OH) is another common base.