Question

$27g$ of $Al$ will react completely with how many grams of oxygen?

• A. $8g$
• B. $16g$
• C. $32g$
• D. $24g$

Answer 1

Answer: (D)

$4Al+3O_2\to 2A{l}_2{O}_3$
$At.Wt.ofAl=27$
Thus $4\times 27g$ of $Al$ reacts with oxygen $=3\times 32g$
$\therefore 27g$ of $Al$ reacts with oxygen$=\frac{3\times 32}{4\times 27}\times 27=24g$