alkalinity

Examples of alkalinity in the following topics:

• The Alkaline Earth Metals

  • The alkaline earth metals comprise the group 2 elements.
  • All the discovered alkaline earth metals occur in nature.
  • In chemical terms, all of the alkaline metals react with the halogens to form ionic alkaline earth metal halides.
  • All the alkaline earth metals except beryllium also react with water to form strongly alkaline hydroxides which should be handled with great care.
  • The heavier alkaline earth metals react more vigorously than the lighter ones.

• Dry Cell Battery

  • Another example of a dry-cell battery is the alkaline battery.
  • Alkaline batteries are almost the same as zinc-carbon batteries, except that the electrolyte used is potassium hydroxide (KOH) rather than ammonium chloride.
  • In some more modern types of so-called "high-power" batteries that have a much lower capacity than standard alkaline batteries, the ammonium chloride is replaced by zinc chloride.

• Other Rechargeable Batteries

  • Different types include lead-acid, nickel-cadmium (NiCd), nickel-metal hydride (NiMH), lithium-ion (Li-ion), lithium-ion polymer (LiPo), and rechargeable alkaline batteries.
  • There are also rechargeable forms of alkaline batteries, which are a type of primary battery dependent upon the reaction between zinc (Zn) and manganese dioxide (MnO2).
  • Rechargeable alkaline batteries can also have a high recharging efficiency and have less environmental impact than disposable cells.

• Buffers Containing a Base and Conjugate Acid

  • An alkaline buffer can be made from a mixture of the base and its conjugate acid, but the formulas for determining pH take a different form.
  • An alkaline buffer can be made from a mixture of a base and its conjugate acid, similar to the way in which weak acids and their conjugate bases can be used to make a buffer.
  • Calculate the pH of an alkaline buffer system consisting of a weak base and its conjugate acid.

• The Arrhenius Definition

  • The Arrhenius definitions of acidity and alkalinity are restricted to aqueous solutions and refer to the concentration of the solvated ions.
  • In addition, under the Arrhenius definition, a solution of sodium amide (NaNH2) in liquid ammonia is not alkaline, despite the fact that the amide ion ($\text{NH}_2^-$) will readily deprotonate ammonia.

• Strong Bases

  • Common examples of strong Arrhenius bases are the hydroxides of alkali metals and alkaline earth metals such as NaOH and Ca(OH)2.
  • Generally, the alkali metal bases are stronger than the alkaline earth metal bases, which are less soluble.

• Salts that Produce Acidic Solutions

• Hydroboration Reactions and Oxidations

  • Further addition to the resulting boron-substituted alkene does not occur, and the usual oxidative removal of boron by alkaline hydrogen peroxide gives an enol which rapidly rearranges to the aldehyde tautomer.

• Oxidation

  • All these cation oxidations must be conducted under alkaline conditions.

• Soaps & Detergents

  • Solutions of alkali metal soaps are slightly alkaline (pH 8 to 9) due to hydrolysis.
  • Also the sulfonate functions used for virtually all anionic detergents confer greater solubility on micelles incorporating the alkaline earth cations found in hard water.