Answer:
The stoichiometric coefficient for aluminum, Al when the chemical equation is balanced is 2.
To obtain the stoichiometric coefficient for aluminum, we shall write and balance the equation for the reaction. This is illustrated below:
Aluminum => Al
Iron (II) chloride => FeCl₂
Aluminum chloride => AlCl₃
Iron => Fe
Aluminum + Iron (II) chloride —> Aluminum chloride + Iron
Al + FeCl₂ –> AlCl₃ + Fe
There are 3 atoms of Cl on the right side and 2 atoms on the left side. It can be balance by writing 3 before FeCl₂ and 2 before AlCl₃ as shown below:
Al + 3FeCl₂ –> 2AlCl₃ + Fe
There are 2 atoms of Al on the right side and 1 atom on the left. It can be balance by writing 2 before Al as shown below:
2Al + 3FeCl₂ –> 2AlCl₃ + Fe
There are 3 atoms of Fe on the left side and 1 atom on the right side. It can be balance by writing 3 before Fe as shown below:
2Al + 3FeCl₂ –> 2AlCl₃ + 3Fe
Now, the equation is balanced.
The coefficient of Aluminum, Al in the balanced equation is 2.