the pH scale and salts

• OH- = alkaline

  H+ = acidic
• how can the pH of a solution be measured?

  • pH probe
  • universal indicator
• soluble bases are called alkalis and acids are neutralised by bases
• acid + metal hydroxide --> salt + water
• neutralisation reaction:

  H+ + OH- ----> H20

  acid is neutralised by an alkali

  the product is water which has a pH of 7 (neutral)
• acid + metal oxide --> salt + water
• acid + metal carbonate --> salt + water + carbon dioxide
• strong acids are completely ionised (split up into ions) in water
• strong acids:

  • hydrochloric acid
  • nitric acid
  • sulfuric acid
• weak acids:

  • ethanoic acid
  • citric acid
  • carbonic acid