# How many moles of oxygen molecules, O_2, will react with 4.68 mol of aluminium to produce aluminium oxide, Al_2O_3?

The balanced chemical equation is $2 A l + 3 {O}_{2} \to 2 A {l}_{2} {O}_{3}$.
The mole ratio is $\frac{3}{2}$, so $\frac{3}{2} \times 4.68 = 7.02$ mol of ${O}_{2}$ will react with $4.68$ mol of Al.