6.7  Peneutralan


Definition of neutralisation
The reaction of an acid with base or alkali that forms salt and water


Some of the examples:

  • \(HCl + NaOH \rightarrow NaCl+H_2O\)
  • \(H_2SO_4 + CuO \rightarrow CuSO_4 + H_2O\)
  • \(2HNO_3 + Ca(OH)_2 \rightarrow Ca(NO_3)_2 + H_2O\)


Application of neutralisation in daily life


Field Application
Industry Calcium carbonate is used to remove acidic gas such as sulphur dioxide before it is released to the air.
Agriculture Lime or calcium carbonate is used to neutralise acidic soil.
Health Antacids and milk of magnesia are used to neutralise the excess hydrochloric acid in the stomachs of gastric patients.


Acid-base titration

  • Titration is a quantitative analysis that involves the gradual addition of acid into alkali.
  • This technique is used to measure the amount of acid needed to neutralise an amount of alkali.


Apparatus setup for titration


  • Acid-base indicators such as methyl orange and phenolphthalein are used to indicate the completion of the neutralisation. 
  • The common indicators are as follows; 


Indicator Phenolphthalein Methyl orange
Colour in alkali Light pink Yellow
Colour in neutral solution Colourless Orange
Colour in acid Colourless Red