Question

2FeCl2 + Cl2 → 2FeCl3

Answer 1

The reaction

$$2\text{FeCl}_2 + \text{Cl}_2 → 2\text{FeCl}_3$$

is an oxidation-reduction (redox) reaction.

Reduction process, where chlorine is an oxidizing agent:

$$2\text{Cl}^0+2e^-\rightarrow2\text{Cl}^{-1}.$$

Oxidation process, where iron is a reducing agent:

$$2\text{Fe}^\text{II}-2e^-\rightarrow2\text{Fe}^\text{III}.$$