Answer:
Explanation:
To find which of the available reactants is limiting the reaction, you need to compare the ratio of the available reactants with the stoichiometric mole ratio from the chemical equation.
The balanced chemical equation is:
[tex]4Al+3O_2\rightarrow 2Al_2O_3[/tex]
The coefficients of each reactant indicate the stoichiometric mole: 4 moles of Al react with3 moles of O₂.
[tex]4molAl:3molO_2[/tex]
To find the ratio of the available reactants convert the masses in grams to number of moles.
The atomic mass of Al is 26.982g/mol
The molar mass of O₂ is 31.998g/mol
Theoretical ratio
[tex]4molAl/3molO_2\approx 1.333molAl/molO_2[/tex]
Ratio of available reactants
[tex]0.1175molAl/0.07969molO_2\approx 1.47molAl/molO_2[/tex]
Comparison
Since the ratio of the available amount of Al per mol of available O₂ is greater than the theoretical ratio of Al per mol of O₂, there is more available Al than what is needed to react. That implies that when all the O₂ is consumed, there will be some Al left. O₂ is limiting ther reaction.
The reactant that is consumed completely is the limiting reactant, and the reactant that is left is the excess reactant; thus, O₂ is the limiting reactant.
