Chapter 9.2, Problem 18PP

Interpretation Introduction

Interpretation:

Chemical equation for the decomposition of aluminum oxide needs to be determined.

Concept introduction:

In a chemical reaction, the reactants are written on the left side of the equation and the product is written on the right side. The product and the reactants contain an arrow between them showing the proceeding of the reaction from the reactants to the products.

A chemical equation is balanced by balancing the number of moles of each element on the reactants and on the products.

Answer to Problem 18PP

Chemical equation of the given decomposition reaction is as follows:

${\text{2Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(s\right)\to \text{4Al}\left(s\right)\text{+}{\text{3O}}_{\text{2}}\left(g\right)$

Explanation of Solution

Chemical equation of the reaction is as follows:

${\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(s\right)\to \text{Al}\left(s\right){\text{+O}}_{\text{2}}\left(g\right)$

The above equation can be balanced by giving coefficients 2, 4 and 3 to ${\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(s\right)$, $\text{Al}\left(s\right)$ and ${\text{O}}_{\text{2}}\left(g\right)$ respectively.

Thus, the balanced chemical equation will be:

${\text{2Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(s\right)\to \text{4Al}\left(s\right)\text{+}{\text{3O}}_{\text{2}}\left(g\right)$

Aluminium oxide decomposes when electricity passes through it to generate solid aluminium and oxygen gas.

This reaction is a decomposition type reaction. It is because in a decomposition reaction, a compounds breaks down to generate two or more than two new compounds or elements.

Conclusion

Chemical equation of the decomposition reaction,

“Aluminium oxide (s) decomposes when electricity passes through it” is,

${\text{2Al}}_{\text{2}}{\text{O}}_{\text{3}}\to \text{4Al}\text{+}{\text{3O}}_{\text{2}}$

In this reaction, aluminium decomposes on passing electricity to produce aluminium and oxygen.