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