Hydrogen is produced from common materials.
name: Hydrogen is produced in a series of displacement and hydrolysis reactions.
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This experiment demonstrates a way to obtain hydrogen from common materials. When copper sulfate is mixed with sodium chloride the exchange reaction took place. Copper (II) chloride and sodium sulfate are formed. Copper (II) chloride undergoes the hydrolysis reaction. Hydrolysis of salts is an ion exchange reaction of salt and water. Water breaks down the bonds in the salt producing new types of compounds depending on the nature of the initial substance. In the case of salt formed from a strong acid and weak base such as copper (II) chloride the bonds in a salt will break apart and the whole solution turns acidic. In our case some small amount of hydrochloric acid is produced. The driving force of the hydrolysis process is the interaction of ions with water resulting in the formation of a weak electrolyte.
As a rule aluminum foil is not a very reactive material. Aluminum in such a state does not replace metals from their salts even if it stands much higher in the reactivity series. The reason of such behavior is the presence of an oxide layer on aluminum surface. It protects the metal from reacting with other chemicals. If you place some aluminum foil to the copper sulfate solution nothing will happen. The Reaction does not proceed. But if you take copper chloride solution instead of copper sulfate the reaction starts immediately. The reason of this is the formation of complex ions between aluminum and chlorine ions which serve as very good ligands helping to destroy the oxide layer. Since aluminum becomes unprotected it readily reacts with hydrochloric acid and copper (II) chloride. In both reactions aluminum is more reactive and displaces hydrogen and copper from their compounds. Aluminum chloride, copper and hydrogen are formed.