Acids and bases

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Subject classification: this is a chemistry resource.
Topics in acids and bases
pH edit

In chemistry, a compound could be an acid or a base. Acids and bases are very important in chemistry. They describe a large class of substances. Understanding their properties allows us to rationalize patterns that occur in chemistry.

Contrasting properties of acids and Alkalis[edit | edit source]

Here is a list which contrasts their properties:

  • Acids turn blue litmus paper red. Bases turn red litmus paper blue.
  • Acids give off H+ (Hydrogen) ions in water; bases give off OH- (Hydroxide) ions in water.
  • Acids generally taste sour due to the sour H+ ion; bases taste bitter due to the OH- ion; but they may have other tastes depending on the other part of the molecule.
  • Bases are usually soapy in nature.
  • Acids corrode active metals ; Bases denature protein.
  • Acids have a pH less than 7 ; Bases have a pH greater than 7

Similar properties of acids and Alkalis[edit | edit source]

Here is a list of properties that are common to both acids and bases

  • When you dissolve an acid or base in water, it makes ions. This makes the water conduct electricity better.
  • The stronger the acid (or base), the more ions are produced, so the conductivity of the solution increases.
  • They can both conduct electricity.
  • When an acid reacts with a base, a salt is formed
  • They both can carry and share ions

Things unique to acids[edit | edit source]

Acids react with group 1 and 2 metals to generate hydrogen gas.

Examples of common things which are acidic[edit | edit source]

  • Citrus fruits (Oranges, Lemons, Limes)
  • Apples
  • Pineapples
  • Mangoes
  • Water and soft drinks (Carbon dioxide reacts in water to form carbonic acid)
  • Stomach acids
  • Vinegar
  • Liquid Drain cleaners containing sulfuric acid (Rooto)
  • Any sour candy

Things unique to Alkalis (bases)[edit | edit source]

Bases feel slippery and soapy and taste bitter because they hydrolyze the fatty acid ester of the skin (saponification reaction).

Examples of common things which are Alkalis[edit | edit source]

  • Lye
  • Baking soda
  • Bleach
  • Ammonia, e.g. window cleaner
  • Wasp's sting
  • Some Drain cleaner (Drano, Red Devil)
  • Tooth paste