Neutralisation
Contents
Key Stage 3
Meaning
Neutralisation is a chemical reaction in which an acid and a base react to produce a neutral product.
About Neutralisation
- Neutralisation can reduce the danger from a corrosive spill.
- An acid can be neutralised by adding a base.
- A base can be neutralised by adding an acid.
- When there is a dangerous acid spill it is better to use an insoluble base to neutralise it than an alkali because if too much is used the insoluble base will not make the solution go above pH 7 but an alkali may neutralise and then replace the acid with another corrosive chemical with a high pH.
- During neutralisation experiments an indicator is added to observe when the solution becomes neutral.
Examples
- Hydrochloric Acid + Lithium Oxide → Lithium Chloride + Water
- Hydrochloric Acid + Iron Oxide → Iron Chloride + Water
- Sulphuric Acid + Potassium Hydroxide → Potassium Sulphate + Water
- Sulphuric Acid + Aluminium Hydroxide → Aluminium Sulphate + Water
- Nitric Acid + Magnesium Carbonate → Magnesium Nitrate + Carbon Dioxide + Water
- Nitric Acid + Titanium Carbonate → Titanium Nitrate + Carbon Dioxide + Water
Key Stage 4
Meaning
Neutralisation is a chemical reaction in which an acid and a base react to produce a neutral product.
About Neutralisation
- The general equation for a neutralisation reaction is:
- Acid + Base → Salt + Water
- When a neutralisation reaction happens in solution the Hydrogen ions and Hydroxide ions react to form water.
Neutralising Acids
- To neutralise an acid it is important to use the right amount of base or alkali to produce a neutral substance. Too much base or alkali and the solution will not be turned alkali instead of neutral.
An acid can be neutralised with:
- Metal - Which can be added to produce Hydrogen gas. Once no more Hydrogen is produced the solution has become neutral.
- Insoluble Carbonates - Which can be added in excess as the reaction will stop when there is no more acid and leave the insoluble Carbonate visible and a neutral solution.
- An alkali with a pH Indicator - Which will change colour showing when the solution is neutral.
Examples
- 2HCl(aq) + Li2O(s) → 2LiCl(aq) + H2O(l)
- 6HCl(aq) + Fe2O3(s) → 2FeCl3(aq) + 3H2O(l)
- H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + H2O(l)
- 3H2SO4(aq) + 2Al(OH)3(aq) → Al2(SO4)3(aq) + 6H2O(l)
- 2HNO3(aq) + MgCO3(s) → Mg(NO3)2(aq) + H2O(l)
- 2HNO3(aq) + TiCO3(s) → Ti(NO3)2(aq) + H2O(l)