2) Neutralisation of acids and salt production

• Soluble bases are called alkalis
•  Acids are neutralised by bases.
• acid + metal hydroxide -> salt + water
• Acids contain hydrogen ions, H+(aq).
• Alkalis contain hydroxide ions, OH-(aq).
• When an acid reacts with an alkali, the H+ and OH- ions react together to produce water, H2O, which has a pH of 7.
• H+(aq) + OH (aq) →→H2O(l)
• This type of reaction is called neutralisation because:

  • acid is neutralised by an alkali
  • the solution that remains has a pH of 7, showing it is neutral.
• Acids can also be neutralised by metal oxides and metal carbonates:

  • acid + metal oxide -> salt + water
  • acid + metal carbonate -> salt + water + carbon dioxide
• A salt is produced when the hydrogen in the acid is replaced by a metal ion.
• • The name of the salt produced depends on the acid used:

  -Hydrochloric acid produces chloride salts.

  -Nitric acid produces nitrate salts.

  -Sulfuric acid produces sulfate salts.