Final answer:
The coefficient of O₂(g) required to balance the chemical equation AlCl₃(g) + O₂(g) → Al₂O₃(s) + ClO(g) is 3.
Step-by-step explanation:
The question is about balancing a chemical equation with aluminum chloride and oxygen to produce aluminum oxide and chlorine monoxide. To find the coefficient of O₂(g) when balancing the reaction, we start by writing the unbalanced equation:
AlCl₃(g) + O₂(g) → Al₂O₃(s) + ClO(g)
We notice that the aluminum and chlorine atoms are not balanced. To balance the aluminum atoms, 2 molecules of aluminum chloride must react to form 1 molecule of aluminum oxide. Then, chlorine is balanced by having 3 molecules of ClO for every 2 of AlCl₃, which leaves us with:
2 AlCl₃(g) + O₂(g) → Al₂O₃(s) + 3 ClO(g)
Now we balance the oxygen atoms. There are 3 O atoms on the right side from the ClO, plus another 3 from the Al₂O₃, totaling 6 oxygen atoms. Therefore, we need 3 O₂ molecules to balance the oxygen, giving us:
2 AlCl₃(g) + 3 O₂(g) → Al₂O₃(s) + 3 ClO(g)
The coefficient of O₂(g) when the chemical equation is balanced using the smallest whole number integer coefficients is 3.