This is an **oxidation-reduction** (redox) reaction:

**Cl**VII + *8* **e**- → **Cl**-I *(reduction)*

*4* **O**-II - *8* **e**- → *4* **O**0 *(oxidation)*

*KClO4* is an **oxidizing** agent, *KClO4* is a **reducing** agent.

### Word equation

*potassium perchlorate → potassium chloride + oxygen*

### Input interpretation

*KClO4 → KCl + O2*

* Potassium perchlorate potassium chloride oxygen *

### Balanced equation

Balance the chemical equation algebraically:

*KClO4 → KCl + O2*

Add stoichiometric coefficients, c, to the reactants and products:

*c1KClO4 → c2 KCl + c3O2*

Set the number of atoms in the reactants equal to the number of atoms in the products for *Cl, K and O:*

*Cl: c1 = c2*

*K: c1 = c2*

*O: 4c1 = 2c3*

Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set** c1 = 1** and solve the system of equations for the remaining coefficients:

*c1 = 1 c2=1*

*c3=2*

Substitute the coefficients into the chemical reaction to obtain the balanced

equation:

**Answer**:

*KClO4 → KCl + O2*