E.G. 2HCL(aq) + Mg(s) → MgCL2(aq) + H2(g)
Hydrochloric Acid + Magnesium → Magnesium Chloride + Hydrogen
Method 2 : Acid + Insoluble Base
- Neutralisation reaction
-
When Acid and Base react → Salt and Water is formed
- The salt made depends on the acid used and the metal in the base/alkali
- (e.g. Nitric acid always make nitrate, Sulfur acid always make sulfate, Hydrochloric acid always make chloride)
- (e.g. Base contain Sodium ions always make sodium salt, base contain Potassium ions always make potassium salt)
Acid + Base → a Salt + Water
E.G. 6HCL(aq) + Fe2O3(s) → 2FeCL3(aq) + 3H2O(l)
Hydrochloric Acid + Solid Iron(III) Oxide → Iron(III)Chloride Solution + Water
Method 3 : Acid + Alkali (Soluble Base)
- Neutralisation reaction (Titration)
- An indicator can be used (Neutralisation Point is when the indicator changes colour)
- The solution of the weakly alkaline solution is evaporated to form a saturated solution and then it is left to crystalise
Neutralisation
- H+(aq)ions reacting with OH-(aq) ions to form water
- H+(aq) + OH-(aq) → H2O (l)
Acid + Base → a Salt + Water
E.G. HNO3(aq) + NH4+(aq) → NH4NO3(aq) + H20(l)
Nitric Acid + Ammomia Solution → Ammonium Nitrate + Water
Method 4 : Precipitation to make Insoluble Salt
- Insoluble salt can be made by reacting 2 solutions of soluble salts to produce a precipitate (insoluble solid)
- Precipitation reaction
- We need to know about the solubility of salt to decide whether a salt in soluble/insoluble
AZ(aq) + BY(aq) → AY(s) + BX(aq)
* AX, BY, BX are soluble(aq) & AY is insoluble(s)
E.G. Pb(NO3)2(aq) +2KL(aq) → Pbl2(s) + 2KNO3(aq)
Lead Nitrate Solution + Potassium Iodide Solution → Lead Iodide Precipitate + Potassium Nitrate Solution
