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

* PbII + 2 e- → Pb0 (reduction)*

* 2 Cl-I - 2 e- → 2 Cl0 (oxidation)*

** PbCl2** is both an

**oxidizing**agent and

**reducing**agent.

### Word equation

* lead(II) chloride → lead + chlorine*

### Input interpretation

* PbCl2 → Pb + Cl2*

* lead(II) chloride lead chlorine*

### Balanced equation

Balance the chemical equation algebraically:

* PbCl2 → Pb + Cl2*

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

* c1PbCl2 → c2Pb + c3Cl2*

Set the number of atoms in the reactants equal to the number of atoms in the products for ** Cl **and

*Pb:**Cl: 2c1 = 2c3*

*Pb: c1 = c2*

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 = 1*

Substitute the coefficients into the chemical reaction to obtain the balanced

equation:

** Answer**:

* PbCl2 → Pb + Cl2*