Question

One mole of potassium chlorate $KCl{O}_3$ is thermally decomposed and excess of aluminium is allowed to react with gaseous product. How many mole(s) of aluminium oxide $A{l}_2{O}_3$ is/are formed?

• A. 1
• B. 1.5
• C. 2
• D. 3

Answer 1

The correct option is A 1

The thermal decomposition of $KCl{O}_3$ is given as:
$2KCl{O}_3\left(s\right)⟶2KCl\left(s\right)+3O_2\left(g\right)$
The gaseous product i.e. $O_2\left(g\right)$ reacts with excess of $Al$:
$3O_2\left(g\right)+4Al\left(s\right)⟶2A{l}_2{O}_3\left(s\right)$
As per the stoichiometric data, 1 mole of $KCl{O}_3$ will give $\frac{3}{2}$ mole of $O_2$, which in turn, yields 1 mole of $A{l}_2{O}_3$.