# What is the molar ratio for the chemical reaction Al + O_2 -> Al_2O_3?

Dec 20, 2015

Aluminum to oxygen is 0.666

#### Explanation:

Balance the equation

4Al + $3 {O}_{2} \rightarrow 2 A {l}_{2} O 3$

In the reactant side 4 Al reacts with six oxygen atoms to for two molecules of $A {l}_{2} {O}_{3}$

Mole ratio Al to oxygen = No of atoms of Al in $A {l}_{2} {O}_{3}$$\div$ No of atoms of Oxygen in $A {l}_{2} {O}_{3}$

Hence Al to O2 mole ratio 2$\div$3 = 0.666