Question

Aluminium reacts with oxygen to form aluminium oxide. How many moles of oxygen required to react completely with $0.5$ moles of aliminium?

• A. $\frac{2}{3}\text{moles}$
• B. $\frac{3}{8}\text{moles}$
• C. $\frac{2}{5}\text{moles}$
• D. $\frac{7}{8}\text{moles}$

Answer 1

The correct option is B $\frac{3}{8}\text{moles}$

The reaction incolved is:
$4Al+3O_2\to 2A{l}_2{O}_3$
$4$ moles of $Al$ react with $3$ moles of $O_2$
$0.5$ moles of $Al$ react with $\frac{3}{4}\times 0.5=\frac{3}{8}$ moles of $O_2$