Question

$9g$ of Al will react, with ____ .

$2Al+\frac{3}{2}{O}_2\to {Al}_2{O}_3$

• A. $6g$ $O_2$
• B. $8g$ $O_2$
• C. $9g$ $O_2$
• D. $4g$ $O_2$

Answer 1

Answer: (B)

$8g$ $O_2$

$2A{l}_{\left(s\right)}+\frac{3}{2}{O_2}_{\left(g\right)}⟶{{Al}_2{O}_3}_{\left(s\right)}$

From the reaction, we know that 2 moles of $Al$ react with 1.5 moles of $O_2$ and forms 1 mol of $A{l}_2{O}_3$

Atomic mass of Al= 27 g/mol

So, amount of oxygen to react with 54 g Aluminium $=48g$

$\Rightarrow$ Amount of oygen to react with 9 g Aluminium $=\frac{48}{54}\times 9=8g$

Hence, 9 g $Al$ will react with 8g $O_2$.

So, the correct option is B