Alkali

From Wikipedia, the free encyclopedia
Jump to: navigation, search

In chemistry, an alkali is an aqueous (from water) solution with a pH value of more than seven. The word 'Alkali' comes from the Arabic 'qali' meaning 'from the ashes' since ashes mixed with water used as cleaning products (such as soaps) are made of alkali materials

An alkali is where a base is dissolved in water. Often it is the salt of an Alkali metal
An alkali is the opposite to an acid and can be neutralised (brought down to pH 7) by adding acid.

Characteristics[change | change source]

  • It feels soapy
  • It is corrosive (it can burn your skin away)
  • The higher the number is over 7 on the pH scale the stronger the alkali is.
  • Highly soluble (can be dissolved) in water
  • They have a bitter taste
  • Turns red litmus paper blue
  • Can conduct electricity due to the presence of mobile ions
  • Is blue or purple on universal indicator

Strength of an Alkali[change | change source]

Someone can find out how strong or weak an alkali is by adding universal indicator to it. Some universal indicators can be poured into alkalis and some are soaked into paper, and the paper is touched to the alkali.

For example, soap and toothpaste are minor-strength alkalis. Lye is a strong alkali.

Sodium Hydroixide

Examples of common Alkalis[change | change source]

Uses of common Alkalis[change | change source]

Oxides and Hydroxides[change | change source]

Metal oxides and metal hydroxides are two types of base. When neutralised (an acid is added) they produce a salt and water. The type of salt produced depends on the acid and base.

Related pages[change | change source]

Other websites[change | change source]