Cr2O72- + Fe2+ → Cr3+ + Fe3+
Substance oxidized Fe^2+ Substance reduced Cr2O7^2-
Oxidizing agent Cr2O7^2- Reducing agent Fe^2+
In the given reaction, Fe2+ is oxidized to Fe3+ and Cr2O72- is reduced to Cr3+. Therefore, Fe2+ is the substance that is oxidized, while Cr2O72- is the substance that is reduced.
The oxidizing agent is Cr2O72- because it causes the oxidation of Fe2+. It is referred to as an oxidizing agent because it accepts electrons from Fe2+ and gains electrons itself, leading to a reduction.
On the other hand, Fe2+ is the reducing agent because it causes the reduction of Cr2O72-. It is called a reducing agent because it loses electrons to Cr2O72- and itself gets oxidized.
Overall, the reaction involves a transfer of electrons from Fe2+ to Cr2O72-, resulting in the formation of Fe3+ and Cr3+.